Let us consider an example in which particle is projected vertically upward from ground at t=0 and it reaches highest point at t=2. Then, at that instant (t=2) velocity v=0, but acceleration =−g. Here, displacement is non zero for the duration t=0 to t=2. For t>2 the ball again acquires velocity. In this example option (a), (b) and (d) are correct. Let us consider another example in which a particle is moving on horizontal plane and it comes to rest. permanently at t=1, then this is one of the special case in which acceleration of particle is zero at t=2.