The correct answer is: B. He was made a king by them.
The sentence “They made him a king” is in the passive voice. In the passive voice, the subject of the sentence is acted upon by the verb. In this case, the subject is “he” and the verb is “made.” The direct object of the sentence is “king.”
The passive voice can be used to focus on the action of the sentence rather than the person or thing doing the action. In this case, the focus is on the fact that “he” was made a king, not on who made him a king.
The other options are incorrect because they are in the active voice. In the active voice, the subject of the sentence is doing the action. In these cases, the subjects are “he,” “they,” and “him.”
The active voice can be used to focus on the person or thing doing the action. In these cases, the focus would be on the fact that “he” made a king, “they” made a king, or “him” made a king.
However, the original sentence is in the passive voice, so the correct answer is B. He was made a king by them.