When a baseball flies through the air after being hit, it primarily has kinetic energy due to its motion.
However, it's important to note that the baseball also possesses mechanical energy as a broader category, which includes both kinetic energy (due to its motion) and potential energy (related to its height above the ground).
In the context of your question, if you are looking for the type of energy specifically related to the motion of the baseball, the best answer is kinetic energy.