Two possible reasons for Akhenaten changing to a monotheistic belief system are: he really did believe there was only one god and he feared the wealth and power of the priests.
Akhenaten known before the fifth year of his reign as Amenhotep IV, was an Ancient Egyptian pharaoh of the Eighteenth Dynasty who ruled for 17 years and died perhaps in 1336 BC or 1334 BC.
The correct answers between all the choices given are the 2nd and last choices or B and D. I am hoping that this answer has satisfied your query and it will be able to help you in your endeavor, and if you would like, feel free to ask another question.