Farmers Often Practice Crop Rotation to Help Enrich Agricultural Fields

Multiple Choice

Farmers often practice crop rotation to help enrich agricultural fields.Why are beans and other legumes often used in the rotations?

A) Beans fix nitrogen.
B) Bacteria in legume root nodules are nitrifiers.
C) Legumes enrich the soil by forming heterocysts.
D) Legumes remove toxins from the soil.