Explanation:

- Let's break it down step by step:

- T sits immediately to the left of Q.

- Only one person sits between T and P.

- Two persons sit between T and S.

- Number of persons to the left of Q is one less than to the right of Q, hence Q is third from the left.

- V sits second to the right of U.

- W is not an immediate neighbour of V.

Considering these conditions, we can deduce:

1. Q is in the third position, making T second, and both having P or S as potential neighbors.

2. With V sitting second to the right of U, U can't be near the end.

3. W can't be an immediate neighbor to V.

After mapping out possibilities:

- R will be at the extreme left position.

- S will be at the extreme right position.

Hence, R sits at the extreme end of the row. Option 2: R is the correct answer.