The correct answer is: B. these allowed them to collect rain, runoff, and flood waters to irrigate their crops when needed.
The Aztecs developed an extensive system of canals and channels, particularly in their capital city, Tenochtitlán, which was built on a lake. These waterways were crucial for irrigation, allowing them to manage water supply for their crops and support agriculture in a challenging environment. They were able to collect rainwater and direct excess water from flooding to irrigate fields, which was essential for their agriculture-dependent society.