Los beisbolistas de una base a otra.
question 1 options:
a) 
batean
b) 
corren

For this case we can translate the given sentence as:

Baseball players from one base to another.

We must complete the sentence with the most appropriate verb, we have the following options:

Logically, in a baseball game the bases must be run by the players, so the correct option is "corren"

Los beisbolistas corren de una base a otra.