Answer:
D. alfalfa
Explanation:
Alfalfa is a plant that is widely used around the world for grazing purposes. The crop has several very favorable characteristics. Although it requires rotation, it is high in minerals and provides excellent grass feed for cattle.
Alfalfa has also proven to be drought-resistant thanks to its deep roots. But, maybe the most important advantage alfalfa has over competing crops is the ability to produce its own nitrogen. This eliminates the need for nitrogen-based fertilizers.
