GMAT Sentence Correction (SC) | Re: Alumni that earn bachelor’s degrees from a large state institution are

Alumni that earn bachelor’s degrees from a large state institution are more likely to attend its alma mater’s sporting events, while alumni from smaller liberal arts colleges frequently show their allegiance by donating money.

(A) Alumni that earn bachelor’s degrees from a large state institution are more likely to attend its alma mater’s sporting events,
(B) Alumni that earn bachelor’s degrees from large state institutions are more likely to attend their alma maters’ sporting events,
(C)