When he _____ from his journey, tell him I want to see him?
Answer Details
The option that best completes the sentence is "returns".
This is because the sentence is in the future tense, indicating that the person in question is currently on a journey and is expected to come back at some point in the future. Therefore, the appropriate verb to use in this context is "returns", which means coming or going back to a place or person after having been away.
The other options do not fit the context of the sentence. "Might have returned" suggests uncertainty or doubt, "returned" implies that the person is already back from the journey, and "must have returned" implies a strong assumption that the person is back from the journey, which may not be the case.