Final answer:
The pharaoh's authority was based on popular consent, as evidenced by the belief in the pharaoh's divine nature and his role as the chief priest.
Step-by-step explanation:
The evidence that the pharaoh's authority was based on popular consent is supported by the belief that the pharaoh was the embodiment of the god Horus. As a divine figure, the pharaoh was thought to have a direct connection to the gods and served as a link between the gods and the people of Egypt. This belief would have likely given the pharaoh legitimacy and popular support, as the people believed that their ruler possessed divine authority.
Additionally, the pharaoh's responsibility to make offerings to the gods to ensure a bountiful flooding of the Nile suggests that the pharaoh had the support and cooperation of the priests and religious institutions in Egypt. This collaboration between the pharaoh and the religious authorities would have likely contributed to the pharaoh's authority and popular consent.
Based on these facts, it can be concluded that the pharaoh's authority was based on popular consent, as the belief in the pharaoh's divine nature and his role as the chief priest would have garnered support from both the people and the religious establishment.