The sentence that requires semicolons instead of commas is:
The captains of the high-school softball team are pitcher, Marisa Martino, outfielder, Rachel Morrison, and catcher, Lisa Fiore.
This is because the sentence includes items that contain commas (the titles and names), which can lead to confusion. Using semicolons helps to clearly separate the different roles and their associated names. Here’s how it would look with semicolons:
The captains of the high-school softball team are: pitcher, Marisa Martino; outfielder, Rachel Morrison; and catcher, Lisa Fiore.