Answer: A. establishing a new, monotheistic religion.
Akhenaten (known as Amenhotep IV before the fifth year of his reign) was an Egyptian pharaoh of the 18th Dynasty. He is particularly well-known for trying to shift the kingdom from a polytheistic, traditional religion to a monotheistic worship centered on the "Aten." After his death, the country went back to its traditional practices and Akhenaten's legacy was destroyed.