P, Q, R, S, T and U are six friends. They are sitting in a row facing south. P is sitting to the immediate left of R and second to the right of S. T is sitting to the immediate right of R. U is sitting second to the left of R. Q is sitting to the immediate left of S. Who is sitting at the extreme right end of the row?

A

T

B

U

C

R

D

Q