What is the correct transformation of 'He has been here before' into an interrogative?

The transformation of the statement "He has been here before" into an interrogative form requires keeping the same meaning while rearranging the words to form a question. The correct choice retains the original verb tense and the subject-verb agreement, making it an appropriate interrogative form.

Option D successfully changes the statement into a question while maintaining the same tense and meaning: "Has he been here previously?" This structure clearly indicates that we are inquiring about his past presence at that location.

Other options do not fulfill the requirements for transforming the sentence correctly. The first option alters the verb tense to past perfect ("Had he been here before?") which changes the intended meaning and timeframe. The second option uses the incorrect verb form ("Have he been here before?"), which does not agree with the singular subject. The third option changes the focus of the inquiry entirely, asking whether he comes here instead of addressing whether he has been here before, thus losing the original question's intent.