Answer:
Correct Answer: D. Answers A and C.
Explanation:
The other guy on this question was incorrect, i failed that question so here is the anwser.
Answer:
These bacteria convert gaseous nitrogen into nitrates or nitrites as part of their metabolism, and the resulting products are released into the environment.
Group of tissues performing a specific task is known as organ and group of organs performing a specific task is organ system.
The process which planetesimals combine with other planetesimals is called Accretion.
There are other names which refer to as accretion. For example, Accretion geology is termed as the increase in the size of a tectonic plate by addition of materials which convergent boundary.
Accretion atmosphere is termed as the process by which water vapor which is in clouds forms water droplets around nucleation sites.
Accretion astrophysics is termed as the formation of planets and other bodies through a collection of material through gravity.
I'm almost 100% it is the first option