Eight persons — A, B, C, D, E, F, G and H were studying about different birds in different months of the same year, viz. January, March, May, June, July, October, November and December, but not necessarily in the same order. Each of them is studying about different birds — Kingfisher, Toucans, Penguin, Ostrich, Woodpecker, Loon, Sparrow and Peacock.

G is studying in the month having odd number of days. Either two persons were studying before G or after G. Two persons were studying between G and the one who is studying about loon. H was studying three persons after the person who is studying about ostrich and four months before A. Three persons were studying between A and the one who is studying about Woodpecker. B is studying about Sparrow two persons before F. F is studying before E. The one who is studying about Penguin is studying immediately after the one studying about Kingfisher. Two persons were studying between the ones studying about Kingfisher and Peacock. D is not the first one to study.

Which among the following combination is correct?

The correct option is C and the one studying about Ostrich.

Let us analyze the information given in the puzzle step-by-step to determine the correct combination of month, person, and bird.

First, let's list the months in order along with the number of days they contain:
1. January (31 days)
2. March (31 days)
3. May (31 days)
4. June (30 days)
5. July (31 days)
6. October (31 days)
7. November (30 days)
8. December (31 days)

Let's process the clues:
- "G is studying in the month having odd number of days (31 days). Either two persons were studying before G or after G."
This means G can be either in the 3rd position (May - 31 days) or the 6th position (October - 31 days). Both May and October have 31 days, which is odd.

- "Two persons were studying between G and the one who is studying about loon."
If G is in May (3rd position): The person studying Loon can be in January (1st) or October (6th).
If G is in October (6th position): The person studying Loon can be in May (3rd) or December (8th).

- "H was studying three persons after the person who is studying about ostrich and four months before A."
"Four months before A" refers to the chronological difference in calendar months. Let's look at the available months:
The difference between H's month and A's month is exactly 4 months.
Let's check the month gaps:
- January (1) to May (5): 4 months difference (January is 4 months before May). So H could be in January and A in May.
- March (3) to July (7): 4 months difference. So H could be in March and A in July.
- June (6) to October (10): 4 months difference. So H could be in June and A in October.
- July (7) to November (11): 4 months difference. So H could be in July and A in November.
Since "H was studying three persons after the person who is studying about ostrich", H cannot be the 1st or 2nd person (since at least 3 persons are before H, meaning H must be at least the 4th person: June, July, October, November, or December).
Thus, H cannot be in January or March. This leaves the following possibilities for (H, A):
Case 1: H is in June (4th position) and A is in October (6th position).
Case 2: H is in July (5th position) and A is in November (7th position).

Let's test Case 1: H is in June (4th) and A is in October (6th).
Since G is either in the 3rd (May) or 6th (October) position, and A is in the 6th position, G must be in the 3rd position (May).
Since H (June, 4th) is studying three persons after the one studying Ostrich, the Ostrich student must be 3 positions before H, which is the 1st position (January).
We are told: "Three persons were studying between A (6th) and the one who is studying about Woodpecker." This puts the Woodpecker student in the 2nd position (March).
"Two persons were studying between G (3rd) and the one who is studying about loon." Since G is 3rd, Loon can be 6th (which is A). So A studies Loon.
"B is studying about Sparrow two persons before F." This means B is studying Sparrow, then there is one person between B and F, so F is two positions after B.
"F is studying before E."
"D is not the first one to study."
Let's fill the positions for persons: [1: _, 2: _, 3: G, 4: H, 5: _, 6: A, 7: _, 8: _]
B must be placed such that F is two positions later. The available open positions are:
- If B is 1st (January), F is 3rd (occupied by G).
- If B is 2nd (March), F is 4th (occupied by H).
- If B is 5th (July), F is 7th (November). This is possible! Let's check: B is 5th, F is 7th. Then since F is before E, E must be 8th (December).
This leaves 1st and 2nd positions open for C and D. Since D is not the first one to study, D must be 2nd (March) and C must be 1st (January).
Let's verify the birds for this setup:
- 1st (January): C - Ostrich
- 2nd (March): D - Woodpecker
- 3rd (May): G - (not Loon, not Ostrich, not Woodpecker)
- 4th (June): H - (not Ostrich, not Woodpecker, not Loon)
- 5th (July): B - Sparrow
- 6th (October): A - Loon
- 7th (November): F - (not Sparrow)
- 8th (December): E - (not Sparrow)
Now let's check the remaining bird clues:
"The one who is studying about Penguin is studying immediately after the one studying about Kingfisher."
"Two persons were studying between the ones studying about Kingfisher and Peacock."
Let's look at the available bird slots: G (3rd), H (4th), F (7th), E (8th).
Since Kingfisher and Penguin are consecutive, they must be either in (3rd, 4th) or (7th, 8th).
Subcase 1a: Kingfisher is 3rd (G) and Penguin is 4th (H).
Then, "Two persons were studying between the ones studying about Kingfisher (3rd) and Peacock." This puts Peacock in the 6th position. But the 6th position is already occupied by Loon (A). So this is invalid.
Subcase 1b: Kingfisher is 7th (F) and Penguin is 8th (E).
Then, "Two persons were studying between the ones studying about Kingfisher (7th) and Peacock." This puts Peacock in the 4th position (H). This is valid!
Thus, the remaining bird Toucans must be studied by G in the 3rd position (May).
Let's check if all conditions are satisfied:
- January: C (Ostrich)
- March: D (Woodpecker)
- May: G (Toucans)
- June: H (Peacock)
- July: B (Sparrow)
- October: A (Loon)
- November: F (Kingfisher)
- December: E (Penguin)

Let's double-check all clues against this arrangement:
1. G (May, 3rd) is in a month with odd days (31). Correct.
2. Either two persons studied before G (Jan, Mar) or after G. Two persons studied before G. Correct.
3. Two persons studied between G (3rd) and Loon (6th). Correct.
4. H (June, 4th) studied three persons after the person studying Ostrich (Jan, 1st). Correct (positions 1 and 4 have a gap of 2, so H is 3rd after 1st: 1 + 3 = 4).
5. H (June) is 4 months before A (October). Correct (June to October is 4 months).
6. Three persons studied between A (6th) and Woodpecker (2nd). Correct (positions 3, 4, 5 in between).
7. B (5th, Sparrow) is two persons before F (7th). Correct (5 + 2 = 7).
8. F is studying before E (8th). Correct (7 is before 8).
9. Penguin (8th) is immediately after Kingfisher (7th). Correct.
10. Two persons studied between Kingfisher (7th) and Peacock (4th). Correct.
11. D is not the first one to study (D is 2nd). Correct.

From this correct sequence, we find that C is studying about Ostrich in the month of January. Therefore, the combination of C and Ostrich is correct.