Six boxes M, N, O, P, Q and R are placed one above the other. The lowermost box is numbered 1, the box above it is numbered 2, and so on. Only three boxes are kept below box M. Box N is kept just above box Q. Box P is kept just below box R, which is box number 3.
Which box is kept at the bottom?
1
Box O
2
Box Q
3
Box P
4
Box N