Step 1: Understanding the Concept:
This is a linear seating arrangement problem. We use the given clues to fix the positions of individuals relative to each other on a line.
Step 2: Detailed Explanation:
1. There are 7 positions, numbered 1 to 7 from left to right.
2. B sits at the extreme right end of the row: B is at position 7.
3. G sits second to the left of B: G is at position $7 - 2 = 5$.
4. E sits exactly between G and B: Since G is at 5 and B is at 7, E is at position 6.
5. Only two persons sit between F and G: G is at 5. Two persons to the left of G (positions 4 and 3) means F must be at position 2.
6. D sits third to the left of C: Possible pairs for (D, C) are (1, 4), (2, 5), (3, 6), etc. Since 5 and 6 are occupied, and 2 is occupied by F, the only available pair is D at 1 and C at 4.
7. Remaining person: Only position 3 is vacant, so A must be at position 3.
Final Arrangement: D(1), F(2), A(3), C(4), G(5), E(6), B(7).
Evaluating Statements:
(A) 'F' sits at the extreme left: No, D sits at the extreme left. (Incorrect)
(B) Two persons sit between 'E' and 'F': E is at 6, F is at 2. Between them are 3, 4, 5 (three persons). (Incorrect)
(C) 'C' sits exactly in the middle of the line: Position 4 is the middle of 7. (Correct)
(D) 'E' sits third to the right of 'A': A is at 3. Third right is $3 + 3 = 6$. E is at 6. (Correct)
Only (C) and (D) are correct.
Step 3: Final Answer:
The correct statements are (C) and (D) only, corresponding to option (3).