The correct answers are B) he really believed there was only one God and D) he feared the wealth and power of the Priests.
Two possible reasons for Akehathen changing to a monotheistic system are "he really believed there was only one God and he feared the wealth and power of the Priests."
Akhenaten (1353-1336 BCE) belonged to the 18th Dynasty of Egyptian Pharaohs. His wife was Nefertiti. After five years on power, Akhenaten underwent a major transformation of religious beliefs. He changed the cult from Amun to Aten, installing a monotheistic religion for the first time in Egypt. People did not accept the idea and called him the "heretic king."