He said to me, “Where is the post office?”

The correct answer is C. He asked me where the post office was.

Option A is incorrect because it uses the past tense “wanted” to describe the speaker’s current state of mind. The speaker is asking for information, not expressing a desire.

Option B is incorrect because it uses the word “that” to introduce a question. The speaker is not asking a question, but making a request for information.

Option D is incorrect because it uses the past tense “was” to describe the location of the post office. The speaker is asking for information about the current location of the post office, not its location in the past.