The correct answer is A. He wanted to know what time the offices close.
The sentence “What time do the offices close?” is a question. It is used to ask for information about the time that the offices close. The speaker is asking the listener to provide information about the time that the offices close.
The other options are incorrect because they do not accurately reflect the meaning of the sentence. Option B is incorrect because it uses the past tense form “did”. The sentence is in the present tense, so the past tense form is not appropriate. Option C is incorrect because it uses the past participle form “closed”. The sentence is in the present tense, so the past participle form is not appropriate. Option D is incorrect because it uses the past tense form “did” and the past participle form “closed”. The sentence is in the present tense, so both the past tense form and the past participle form are not appropriate.