To Increase Her Tomato Yield, an Organic Gardener Plants Legumes

To increase her tomato yield, an organic gardener plants legumes alongside her tomato bushes rather than using fertilizers. Why did she plant legumes?

A) Legumes have root nodules with nitrogen-fixing bacteria.
B) Legumes convert ammonium to nitrates.
C) Root nodules on legumes have denitrifying bacteria.
D) Legumes are an immediate source of phosphorus and nitrogen.
E) Root nodules on legumes produce nitrifying bacteria.