In the figure shown, crank AB is 15 cm long and is rotating at 10rad/sec C is vertically above A. CA equals 25cm. C is a swivel trunnion through which BD (40cm.) slides. If ABCD becomes a vertical line during its motion, the angular velocity of the swivel trunnion at that instant will be
(a) Zero (b) (100/25) rad/s
(c) (100/15) rad/s (d) (100/10) rad/s