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 attends immediately before A?

The correct option is D.

Let's step through the logical arrangements of the seven persons (1st to 7th in order of attending the event) based on the given clues:

1. G attends the event three persons after C:
This means there are two persons between C and G. Position layout: C, _, _, G.

2. B attends the event immediately before C:
Combining with clue 1, the order becomes: B, C, _, _, G.

3. Only one person attends the event between B and E:
Since C is immediately after B (B, C), E cannot be placed after B. Therefore, E must be placed two positions before B. Order: E, _, B, C, _, _, G.

4. Count the number of positions in this sequence:
E (1st), _ (2nd), B (3rd), C (4th), _ (5th), _ (6th), G (7th).
This accounts for all 7 persons!

5. D attends the event four persons after E but before A:
Four persons after E (1st position) means position 1 + 4 = 5th position.
So, D is at the 5th position.

6. Three persons attend event between A and F:
Currently, open positions are 2nd and 6th.
If A is at 6th, then 3 persons before 6th (5th, 4th, 3rd) means F would be at 2nd position.
Since D (5th) is before A (6th), this satisfies "D attends before A".

Let's summarize the final order from 1st to 7th:

1st: E
2nd: F
3rd: B
4th: C
5th: D
6th: A
7th: G

Looking at the 5th and 6th positions, D attends at 5th and A attends at 6th. Therefore, D attends immediately before A.