The correct answer is: C. them, we
The pronoun “them” refers to the fruits, and the pronoun “we” refers to the speaker and the person they are talking to. The speaker is remembering that they bought the fruits from someone else.
The other options are incorrect because they do not make sense in the context of the sentence. Option A, “they, we”, would mean that the fruits bought the speaker and the person they are talking to. Option B, “them, us”, would mean that the speaker and the person they are talking to bought the fruits from someone else. Option D, “they, us”, would mean that the fruits bought someone else from the speaker and the person they are talking to.