Six boxes P, Q, R, S, T and U are kept one above the other (not necessarily in the same order). T is kept above Q, but below S. Two boxes are kept between R and U. P is kept just above T. One box is kept between P and U. How many boxes are kept between Q and S?
1
3
2
4
3
2
4
1
5
None of the above/More than one of the above.