Choose the sentence that uses the correct question tag:

You are going out, aren't you?

The correct answer is Option (1) → You are going out, aren't you?

The question tag "aren't you" is correctly used here to confirm the statement made in the first part of the sentence. Since the statement is affirmative ("You are going out"), the question tag should be formed with the negative auxiliary verb "are" and the pronoun "you," followed by the contraction of "not" ("n't"), resulting in "aren't you."

The other options have incorrect question tags:

• "Rajeev will be staying at home. Is he?": The question tag "Is he?" is incorrect because it does not match the tense of the main clause. The main clause is in the future tense ("will be staying"), so the question tag should be formed with "will" as well, resulting in "will he be?"

• "Meena will not be going. won't she?": While the question tag "won't she?" matches the negation of the main clause ("will not be going"), the auxiliary verb "will" in the main clause should be retained in the question tag, resulting in "will she?" instead of "won't she?"

• "They are interested to join us, are they?": The question tag "are they?" is formed correctly to match the present tense of the main clause ("They are interested to join us"). However, the structure of the main clause is awkward. It would be more natural to say "They are interested in joining us" instead of "interested to join us."