Fill in the blank with the most appropriate word.
"What _____ ?"
"I don't know. Look it up."
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 A is correct as the subject is singular (this word) and the given sentence suggests the use of present simple tense (don't know,look). Does is used as an auxiliary verb here, the main verb is mean.
The other options are wrong as they are not structured correctly.
The correct answer is A) does this word mean