A triangular block mass m rests on a fixed rough inclined plane having friction coefficient `mu` with the block. A horizontal force F is applied to it as shown in figure below, then the correct statement is :
A. Friction force is zero when `F cos theta = mg sin theta`
B. The value of limiting friction is `mu (mg sin theta + F cos theta)`
C. Normal reaction on the block is `F sin theta + mg cos theta`
D. The value of limiting friction is `mu (mg sin theta - F cos theta)`
