Explanation:

Correct option:4

Solution:

 (i) All are facing east.

This is basic orientation, but does not help with specific positions.

(ii) C is on the immediate right of D.

Helps to fix the relative positions of C and D.

 (iii) B is at an extreme end and has E as his neighbour.

Gives B and E's positions and helps start/end the sequence.

 (iv) G is between E and F.

Places G relative to E and F.

 (v) D is sitting third from the south end.

Gives D’s exact spot, since there’s a single wall/seating.

Hence all are required to tell the position of A.

The arrangement is as follows:

Hence correct option is 4 all required.