Pick your answer from: (I). Converts oxygen. (II). nutrients. (III). Converts h2o. (IV). Converts nitrogen. (V). Regrows it. (VI). hydrate their cells. (VII). Converts methane. (VIII). competing for resources.
Given those answer options, answer the question: Fact 1: Bacteria in soil convert atmospheric nitrogen into a form usable by plants. Fact 2: Rhizobial bacteria convert atmospheric nitrogen into nitrate fertilizers in a form usable by plants. Given the two facts above, what does rhizobial bacteria do for plants?
A:
(IV).