In which sentence does the verb agree with the subject?
a. grandma or aunt jean visit on almost every holiday.
b. either some grapes or an apple are a healthful snack.
c. appetizers or soup comes with your dinner order.

In the sentences given above, the sentence in which the verb agrees with the subject is letter C: Appetizers or soup comes with your dinner order. Letters A and B have wrong usage of verbs (subject-verb agreement). Verbs are simply known as the ‘action’ words – may it be mental, physical or mechanical. When verbs are paired with auxiliaries (helping verbs), they are known as verb phrase. These helping verbs always go first before the actual verb. In subject-verb agreements, the verb depend on the singularity or plurality of the subject given in a sentence.    

Not sure put the answer in the comments so this person doesn't get there question answered