The coordinate of a particle moving in a plane are given by ` x(t) = a cos (pt) and y(t) = b sin (pt)` where `a,b (lt a)` and `P` are positive constants of appropriate dimensions . Then
A. the path of the particle is an ellipse
B. The velocity and acceleration of the particle are normal to each other at `t=pi//2p`
C. the acceleration of the particle is always directed towards a fixed point
D. the distance travelled by the particle in time interval `t=0` to `t=pi//2p` is a
