Fill in the blank with the most appropriate word.
_____ she already bought a new car?
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 a verb which gives is used in the formation of tenses, moods, tones, etc.
Option B is correct as the subject is singular and new car suggests the use of present perfect tense (bought). Has is used as an auxiliary verb here, the main verb is buy.
The other options are wrong as the main verb is its third form and the subject is not plural.
The correct answer is B)has