Correct option is D
Given:
M sits third to the right of A.
M is second to the left of P.
Only one person sits between P and S.
Q sits to the immediate right of S.
No other person is sitting in the row.
According to the given information seating arrangement will be:
M is third to the right of A-
A _ _ M
A _ _ M
M is second to the left of P-
A _ _ M _ P
A _ _ M _ P
Only one person sits between P and S-
A _ _ M _ P _ S
A _ _ M _ P _ S
Q sits to the immediate right of S, so:
A _ _ M _ P _ S Q.
A _ _ M _ P _ S Q.
There are no other people, so the row is complete.
A, _, _, M, _, P, _, S, Q → Total = 9 people.
A, _, _, M, _, P, _, S, Q → Total = 9 people.

Thus, the correct option is (d) 9