The correct option is D Shrubs and low trees
There are a number of shrubs and low trees that are used for ruminant fodder. Many are nitrogen-fixing, meaning that they can help to regenerate nitrogen depleted soils, and many are also excellent soil binders. As fodder, nitrogen-rich species are generally highly palatable and rich in protein and provide excellent supplementation for goats that are ill or weak, or when forage is not of good quality.