Pyramids were built to O store surplus amounts of grain
O channel water from the river to the fields
O honor pharaohs who had died
O study the movements of the planets

honor pharaohs who had died

Explanation:

During the third and fourth dynasties of the Old Kingdom, Egypt enjoyed tremendous economic prosperity and stability. Kings held a unique position in Egyptian society. Somewhere in between human and divine, they were believed to have been chosen by the gods themselves to serve as their mediators on earth. Because of this, it was in everyone’s interest to keep the king’s majesty intact even after his death, when he was believed to become Osiris, god of the dead. The new pharaoh, in turn, became Horus, the falcon-god who served as protector of the sun god, Ra.

Ancient Egyptians believed that when the king died, part of his spirit (known as “ka”) remained with his body. To properly care for his spirit, the corpse was mummified, and everything the king would need in the afterlife was buried with him, including gold vessels, food, furniture and other offerings. The pyramids became the focus of a cult of the dead king that was supposed to continue well after his death. Their riches would provide not only for him, but also for the relatives, officials and priests who were buried near him.

- From history.com

<3 Enjoy,

    Dea

2018 means 2018 ce or common era

there have been other eras too including bce, which included way more years.