-Native Americans Planted Crops of Corn, Squash, and Beans

-Native Americans planted crops of corn, squash, and beans. The beans increased the level of nitrogen in the soil. The corn required high levels of nitrogen and provided a support for the beans to climb and receive more sunlight. The large leaves on the squash shaded the ground and limited weed growth. This agricultural method

A) is a type of sustainable agriculture.
B) caused mass extinctions.
C) reduced the ecosystem services.
D) created wildlife corridors.
E) increased the number of pests in the fields.