It’s called a branch point, represents where a single lineage evolved into a distinct new one.
Answer: Anxiety disorder
Explanation:Anxiety disorders are a group of mental disorders characterized by significant feelings of anxiety and fear.Anxiety is a worry about future events, and fear is a reaction to current events.These feelings may cause physical symptoms, such as a fast heart rate and shakiness
They help convert nitrogen to nitrate which is usable by living beings. (Living beings can't use regular nitrogen)
I think the answer would be "A"