In an Area with Nitrogen- Poor Soil, Legumes Often Dominate

In an area with nitrogen- poor soil, legumes often dominate over other plants because they

A) have long taproots that can extract nitrogen from deeper down in the soil.
B) have unique access to the large atmospheric pool of nitrogen thanks to their symbiotic bacteria.
C) inhibit the growth of denitrifying bacteria around their roots, thus keeping more nitrate in the soil.
D) do not need nitrogen at all.
E) obtain supplemental nitrogen by trapping insects and other prey.