Native Americans Developed an Agricultural Method Using the Three Sisterscorn

Native Americans developed an agricultural method using the Three Sisterscorn, squash, and beanswhich became the core of their diet. The beans increased the level of nitrogen in the soil. The corn requires high levels of nitrogen and provides a support for the beans to climb and receive more light. The large leaves on the squash shade the ground and limit weed growth. This agricultural method:

A) increases the number of pests in the fields.
B) creates wildlife corridors.
C) is a type of sustainable agriculture.
D) causes mass extinctions.
E) reduces the ecosystem services.