It's A.
They had created a complex irrigation system that included numerous canals that stretched for miles, just for farming.
Answer:
A.They built canals to carry river water to fields several miles away.
Explanation:
The North American Indian people who lived in prehistoric time occupied the semi-arid region along the river Salt and Gila. A system of complex canal network was used to drawn water from the river to the field. It was their outstanding technological development that made the canal narrow and deeper to prevent evaporation and groundwater absorption.
