A wooden wedge of mass M and inclination anlgle`(alpha)` rest on a smooth floor. A block of mass m is kept on wedge.A force F is applied on the wedge as shown in the figure such that block remains stationary with respect to wedge So, magnitude of froce F is
A. (M+m)g tan `alpha`
B. g tan `alpha`
C. mg cos `alpha`
D. (M+m)g cosec `alpha`
