Select the most appropriate question tag to fill in the blank. You are not…

A question tag must be formed using the same auxiliary verb as the main clause, and its polarity must be the opposite of that clause.

Here the statement is "You are not coming to the party" — it is negative and uses the auxiliary verb "are" (the be-verb in the present continuous "are coming"). Since the statement is negative, the tag must be positive, and it must reuse the same auxiliary "are" with the pronoun "you".

This gives the positive tag "are you?". The other options use the wrong auxiliaries — "will you" (future/request), "do you" (simple present) and "did you" (simple past) — none of which match the auxiliary "are" in the statement, so the completed sentence is: "You are not coming to the party, are you?"