A horizontal force `F = (mg)/(3)` is applied on the upper surface of a uniform cube of mass `m` and side a which is resting on a rough horizontal surface having `mu = (1)/(2)`. The distance between lines of action of `mg` and normal reaction is

Options

A. `a//2`
B. `a//3`
C. `a//4`
D. none

Answer

B