A verb is used to express an occurrence, action , or state. It is the grammatical centre of the predicate in a sentence.
An auxiliary verb is also called a helping verb. It helps the main verb in many occasions. Sometimes, it is also used as the main verb. It is used in the formation of tenses, moods, tones, etc.
Option B is correct as the subject, 'people' is plural and the sentence states a general question.
The other options are wrong as the subject is not singular and the sentence is not in the past tense.
The correct option is B)are.