The moche people prospered because a. they irrigated crops. b. they built large pyramids. c. they conquered other civilizations. d. they discovered gold.

a. they irrigated crops.

Explanation: The Moche cultural sphere was concentrated in several valleys along the northern coast of Peru and occupied 250 kilometers of desert coast that extended up to 50 miles inland. The Moche society was based on agriculture, but because of the arid climate, they invested heavily in building a network of irrigation canals. These ornate canals redirected water from the river to crops throughout the region.