A cat runs along a straight line with constant velocity of magnitude v. A dog chases the cat such that the velocity of dog is always directed towards the cat. The speed of dog is `u` and always constant .At the instant both are separated by distance x and their velocities are mutually perpendicular, the magnitude of acceleration of dog is.

Options

A. `(d)/(3) d//3`
B. `(d)/(2) d//2`
C. `(d)/( 4) d//4`
D. zero

Answer

B