A mass m rests under the action of a force F as shown in the figure-2.158 on a horizontal surface. The coefficient of friction between the mass and the surface is `mu`. The force of friction between the mass and the surface is :
A. `mumg`
B. `mu[mg+(F)/(2)]`
C. `(Fsqrt(3))/(2)`
D. `mu[mg-(F)/(2)]`
