A particle is moving along a straight line. The displacement of the particle becomes zero in a certain time $(t>0)$ The particle does not undergo any collision.

Which of the following statements is the correct statement about the motion of the particle?

Since the particle moves along a straight line and the displacement becomes zero at a point $(t>0)$, we can conclude that the particle must stop and pass through the same point again for the displacement to be zero
Therefore, the velocity of the particle must be zero at some point in order for the particle to stop and start its journey backward. 

The acceleration of a particle is not always zero because the particle needs to change the direction of the velocity to make the displacement zero.

The acceleration will not be constant as the direction of the acceleration will change. 

Therefore answer B is the only correct option.