Seven persons — A, B, C, D, E, F and G — are attending an event one after another, but not necessarily in the same order.
G attends the event three persons after C. B attends the event immediately before C. Only one person attends the event between B and E. D attends the event four persons after E but before A. Three persons attend event between A and F.

Who among the following is the second person in sequence to attend the event?

The correct option is F.

Let us step-by-step determine the order of the seven persons (numbered 1 to 7 from first to last to attend the event):

1. "G attends the event three persons after C."
This means there are two persons between C and G:
$\text{C},\text{\_},\text{\_},\text{G}$

2. "B attends the event immediately before C."
So, B and C form a block (B, C):
$\text{B},\text{C},\text{\_},\text{\_},\text{G}$

3. "Only one person attends the event between B and E."
Since C immediately follows B, E cannot be placed after B (position of C is occupied). Therefore, E must attend before B with one person between them:
$\text{E},\text{\_},\text{B},\text{C},\text{\_},\text{\_},\text{G}$
Counting the positions in this arrangement: E (1st), _ (2nd), B (3rd), C (4th), _ (5th), _ (6th), G (7th). This fills all 7 positions!

4. "D attends the event four persons after E but before A."
Four persons after E means D is at position 1 + 4 = 5th position.
So, position 5 is occupied by D:
1st: E
2nd: _
3rd: B
4th: C
5th: D
6th: _
7th: G

5. "Three persons attend event between A and F" and "D attends ... before A."
Since D (5th) is before A, A must be placed after D. The available remaining positions are 2nd and 6th.
Since A is after D, A must be in the 6th position.
Placing A at 6th position:
1st: E
2nd: _
3rd: B
4th: C
5th: D
6th: A
7th: G

6. Position of F:
Three persons attend between A (6th position) and F. Counting backwards: 5th, 4th, 3rd are the three persons between them, placing F in the 2nd position (6 - 4 = 2).
This completes the arrangement perfectly!

Final Sequence (1st to 7th):
1st: E
2nd: F
3rd: B
4th: C
5th: D
6th: A
7th: G

Thus, the second person in sequence to attend the event is F.