F is sitting to the immediate right of D.
Let's place the 8 persons in positions numbered 1 to 8 in a counter-clockwise direction, assuming everyone is facing the center (where moving counter-clockwise means moving to the right, and moving clockwise means moving to the left)
1. Place A & C: Put A at position 1. Since C is second to the right of A, C is at position 3.
2. Place E: E is opposite C, so E is at position 7.
3. Place F: F is to the immediate left (clockwise) of E, which puts F at position 6.
4. Place B: B is to the immediate right (counter-clockwise) of A, placing B at position 2.
5. Place G & D: We have positions 4, 5, and 8 remaining empty. The clue states "G is to the immediate left of D". The only two adjacent empty spots where G can sit to the left (clockwise) of D are positions 4 and 5. This means D is at position 5 and G is at position 4.
6. Place H: The final remaining spot, position 8, goes to H.
