A bead of mass m is released from rest at A to move along the fixed smooth circular track as shown in figure. The ratio of magnitudes of centripetal force and normal reaction by the track on the bead at any point `P_0` described by the angle `theta(!=0)` would
A. (a) Increase with `theta`
B. (b) Decrease with `theta`
C. (c) Remain constant
D. (d) First increase with `theta` and then decrease