Final answer:
Ancient Egyptians needed to keep track of time for religious ceremonies, predicting natural disasters, and regulating agricultural activities.
Step-by-step explanation:
Ancient Egyptians needed to keep track of time for a variety of reasons. First, they used timekeeping to organize religious ceremonies and festivals, as their religious practices followed specific calendars. Second, tracking time was important for predicting natural disasters like floods and droughts. By understanding cycles of the Nile River's flooding, they could prepare for agricultural activities and ensure successful harvests. Therefore, the correct answer is d) All of the above.