C. They provide instructions for protein synthesis and determine traits.
It is about 4.22 light-years<span> from Earth and is the closest star other than the sun. Alpha Centauri A and B orbit a common center of gravity every 80 years. The average distance between them is </span>about 11 astronomical units<span> (AU) — about the same distance as the sun is to Uranus.</span>
The question is asking the determine the role that the United States do in the ecosystem base on the passage and situation in the question that you have state, base on my research, I would say that its role is a Dominant. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarification
The answer is B. Hope this helps!
Reasoning: Brown Algae and Dinoflagellates are both on the same branch, unlike other answers.
A,b I think should be the answer