A verb is used to express an occurrence, action, or state. It is the grammatical center of the predicate in a sentence.

An auxiliary verb is a verb which gives is used in the formation of tenses, moods, tones, etc.

Option A is correct as the sentence talks about something in general. Therefore, only simple present tense can be used. Also, the subject is singular ( neither= not even one).

The other options are wrong as no other tense can be used here.

The correct answer is A)is