Correct option is C
Given:
- A certain number of people are sitting in a row, facing north.
- Q is second to the right of P.
- Only three people sit between Q and S .
- T is fourth to the right of S .
- If no other person is sitting in the row,
- what is the total number of people seated in the row?
According to the given instructions, the arrangement is as follows:

So, total number of persons in row is 11.
Thus, the correct answer is (c).