Fill in the blank with the most appropriate word.
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 is used in the formation of tenses, moods, tones, etc.
Option B is correct as the sentence is a general saying. Therefore, we must use the simple present tense. We won't be using are here as all equals everything and everything equals one.
The other options are wrong as no other tense can be used here.
The correct answer is B) is