JEE Main 2019 Physics question

To mop-clean a floor, a cleaning machine presses a circular mop of radius R vertically down with a total force F and rotates it with a constant angular speed about its axis. If the force F is distributed uniformly over the mop and if coefficient of friction between the mop and the floor is μ, the torque, applied by the machine on the mop is:

• (A)μFR/2
• (B)μFR/3
• (C)μFR/6
• (D)Correct