How does the alien with the baseball bat contribute to the effectiveness of the political cartoon? It suggests that aliens are like people because they play baseball, a human sport.
It uses humor to show that unknown factors keep damaging the probes humans send.
It shows how to cope with the surface of Mars, which is rocky and full of craters.
It exaggerates the size of the bat in relation to the Mars probe in the cartoon.

It uses humor to show that unknown factors keep damaging the probes humans send.

Explanation:

The political cartoon "Mars Probe" by Mike Keefe shows a Mars probe trying to land on the red planet while there are three aliens playing baseball. The one in the middle exclaimed "Get ready! Here comes another one!" to the one with the bat while the third is in the background standing ready to catch anything that hit the bat.

This political cartoon uses humor to show that unknown factors contribute to the damaged condition of the probes sent by humans to Mars.

Thus, the correct answer is the second option.