Read the given information carefully and answer the questions based on it:

Eight persons sit in a row. Four persons face north and rest face south. Three persons sit between A and B and one of them sits at the end of the row. C sits second to the right of B who faces north. D and B face same direction but they do not sit adjacent to each other. E sits third to the left of D and faces opposite direction to D. G sits third to the right of C. Both the immediate neighbors of G face same direction. H sits to the right of F.

If all the persons rearrange their seating positions and now, they sit in alphabetical order from left end of the row (Direction of all persons remain the same), then how many persons will remain on their positions?

The correct option is One.

Let's analyze the clues step-by-step to find the initial seating arrangement of the eight persons in the row.

1. Total persons: 8 persons (say, positions 1 to 8 from left to right).
2. Directions: 4 face North and 4 face South.
3. Clue: "Three persons sit between A and B and one of them sits at the end of the row."
This means either A or B is at an extreme end of the row. Let's analyze the cases:
- Case 1: B is at the left end (position 1). Then A is at position 5.
- Case 2: B is at the right end (position 8). Then A is at position 4.
- Case 3: A is at the left end (position 1). Then B is at position 5.
- Case 4: A is at the right end (position 8). Then B is at position 4.

4. Clue: "C sits second to the right of B who faces north."
Since B faces North, "second to the right of B" means 2 positions to the right of B.
- In Case 1: B is at position 1. C would be at position 3. (Valid)
- In Case 2: B is at position 8. C cannot sit to the right of B. (Invalid)
- In Case 3: B is at position 5. C would be at position 7. (Valid)
- In Case 4: B is at position 4. C would be at position 6. (Valid)

5. Clue: "G sits third to the right of C."
We need to determine the direction of C to place G. C can face North or South.
Let's analyze Case 1 (B at 1, C at 3, A at 5):
- If C faces North, third to the right of C is position 6 (G at 6).
- If C faces South, third to the left (which would be to the right of C facing south) is to the left (towards 1), which is position 3 - 3 = 0 (out of bounds). So if C is at 3, G must be to the right (position 6), which means C must face North.
So, for Case 1: C is at 3 (faces North), G is at 6.
Let's analyze Case 3 (A at 1, B at 5, C at 7):
- If C is at 7 and faces North, third to the right is position 10 (invalid).
- If C is at 7 and faces South, third to the right is position 7 - 3 = 4. So G is at position 4, and C faces South.
Let's analyze Case 4 (B at 4, A at 8, C at 6):
- If C is at 6 and faces North, third to the right is position 9 (invalid).
- If C is at 6 and faces South, third to the right is position 6 - 3 = 3. So G is at position 3, and C faces South.

6. Clue: "E sits third to the left of D and faces opposite direction to D. D and B face same direction but they do not sit adjacent to each other."
B faces North, so D must also face North. D and B cannot be adjacent. E sits third to the left of D. Since D faces North, "third to the left of D" means E is at position (D's position - 3).
Let's test this in our remaining cases:
Test Case 1: B at 1 (North), C at 3 (North), A at 5, G at 6.
The empty positions are 2, 4, 7, 8.
Since D faces North, and E is third to the left of D, D can only be at:
- Position 7: Then E is at 7 - 3 = 4. This is valid! (D is at 7, E is at 4). D and B (1) are not adjacent. E faces opposite to D, so E faces South.
- Position 8: Then E is at 8 - 3 = 5. But position 5 is occupied by A. So this is invalid.
Thus, in Case 1: B at 1 (North), E at 4 (South), A at 5, G at 6, D at 7 (North), C at 3 (North).
Remaining positions: 2 and 8. The remaining letters are F and H.
Let's place F and H. The clue says: "H sits to the right of F."
Also: "Both the immediate neighbors of G face same direction." G is at position 6. The immediate neighbors of G are A (position 5) and D (position 7). D faces North. Therefore, A must also face North.
Let's check the directions so far: B (North), C (North), E (South), A (North), D (North). We already have 4 facing North. Since only 4 face North and 4 face South, all other remaining persons (G, F, H) must face South.
So, G faces South. F and H face South.
We have positions 2 and 8 empty for F and H.
If F is at 2 (faces South) and H is at 8 (faces South):
Since F faces South, the right of F is towards the left (position 1). So H (position 8) is to the left of F, which contradicts "H sits to the right of F".
If F is at 8 (faces South) and H is at 2 (faces South):
Since F faces South, the right of F is towards the left (positions 7, 6, 5, 4, 3, 2, 1). So H at position 2 is indeed to the right of F! This fits perfectly.
Let's double-check all conditions for this arrangement:
Positions: 1: B (North), 2: H (South), 3: C (North), 4: E (South), 5: A (North), 6: G (South), 7: D (North), 8: F (South).
- 8 persons in a row: Yes (B, H, C, E, A, G, D, F).
- 4 face North, 4 face South: North = {B, C, A, D} (4 persons), South = {H, E, G, F} (4 persons). Yes.
- Three persons between A and B: A is at 5, B is at 1. Between them are H, C, E (3 persons). Yes.
- One of A and B is at the end of the row: B is at position 1 (end). Yes.
- C sits second to the right of B who faces North: B is at 1 (North), second to the right of B is 3, where C sits. Yes.
- D and B face same direction (North) but are not adjacent: B is at 1, D is at 7. Yes.
- E sits third to the left of D (7 - 3 = 4) and faces opposite direction to D (E faces South, D faces North). Yes.
- G sits third to the right of C: C is at 3 (North), third to the right is 6, where G sits. Yes.
- Both immediate neighbors of G (A at 5 and D at 7) face same direction (North). Yes.
- H sits to the right of F: F is at 8 (South), right of F is towards the left, H is at 2. Yes.

Thus, the final initial seating arrangement from left to right is:
Position 1: B
Position 2: H
Position 3: C
Position 4: E
Position 5: A
Position 6: G
Position 7: D
Position 8: F

Now, let's rearrange the persons in alphabetical order from left to right (from position 1 to 8):
The alphabetical order of the eight persons {A, B, C, D, E, F, G, H} is:
1: A, 2: B, 3: C, 4: D, 5: E, 6: F, 7: G, 8: H

Let's compare the original positions with the new alphabetical positions:
- Position 1: Original = B, New = A (Changed)
- Position 2: Original = H, New = B (Changed)
- Position 3: Original = C, New = C (Remained Same)
- Position 4: Original = E, New = D (Changed)
- Position 5: Original = A, New = E (Changed)
- Position 6: Original = G, New = F (Changed)
- Position 7: Original = D, New = G (Changed)
- Position 8: Original = F, New = H (Changed)

Only **C** (at position 3) remains in the same position.

Therefore, only one person remains on their position after the rearrangement.