Which statements are not valid for a projectile? Take up (y) as negative.

(a) The projectile has the same x velocity at any given point on its path.
(b) The acceleration of the projectile is positive and decreasing when the projectile is moving upwards, zero at the top, and increasingly negative as the projectile descends.
(c) The acceleration of the projectile is a constant negative value.
(d) The y component of the velocity of the projectile is zero at the highest point of the projectile’s path.
(e) The velocity at the highest point is zero.

EXPLAIN WHY.