Why did the incas build terraces

a. to improve travel and communication through the empire

b. to allow them to build homes on the sides of mountains

c. to make it easier to climb high mountains

d. to increase the amount of fertile farmland

C

Explanation:

Because the Incas lived in the mountains, they had no flat land for farming. They had to build wide step-like areas called terraces for farming. Through terrace farming, the Incas were able to provide for all people in the empire. ... The Incas grew potatoes and other crops that could resist cold nights.

D, to increase the amount of fertile farmland

answer; the correct answer is (travel horizontally);