The forms of revelations are explained in

A.

Q. 40:51

B.

Q. 41:50

C.

Q. 42:51 “It is not given to any human being that Allah should speak to him unless (it be) by revelation, or from behind veil or (that) He send a messenger to reveal what He wills by his leave…” Q. 42:51.

D.

Q. 43:50

Correct answer is C

The forms are explained in Q. 42:51 "It is not given to any human being that Allah should speak to him unless (it be) by revelation, or from behind veil or (that) He send a messenger to reveal what He wills by his leave..." Q. 42:51.