Select the correct direct form of the given sentence.

We asked them who had called them.

We said to them, "Who has called you?"

The correct direct form of the given sentence is: We said to them, "Who has called you?"

This is because direct speech is the exact words that someone spoke. In the direct form, the subject and tense of the verb do not change.

The other options are incorrect because they change the direct form of the sentence in some way:

• We said to them, "Who are calling you?" - This sentence changes the past tense to the present tense.
• We said to them, "Who calls you?" - This sentence changes the tense of the question from present to past.
• We said to them, "Who has called him?" - This sentence changes the subject of the question from "them" to "him."