Why is a baseball thrown by a pitcher considered to have projectile motion?

it gains a lot of kinetic energy.
it has horizontal and vertical motion.
it gets pulled to the ground by gravity.
it moves in a diagonal direction.

It has horizontal and vertical motion.

Explanation:

A projectile is an object which moves in a parabolic path consisting of two independent motions:

- a horizontal motion, which is a uniform motion with constant speed

- a vertical motion, which is an accelerated motion with constant acceleration directed towards the ground

In this case, the baseball has exactly this kind of motion, so it can be considered to be a projectile.