Both the statements are not valid.
When the object’s initial and final position is the same, the displacement can become zero.
The shortest measurable distance between an object’s original and final locations is displacement. It should not be higher than the magnitude of an object’s distance travelled. But it can be equal to the distance that the object moves.
(a) Displacement cannot be zero because the displacement of an object which travels a certain distance and comes back to its initial position is zero.
(b) Its magnitude is greater than the distance travelled by the object because the displacement of an object can be equal to, but never greater than the distance travelled.