Both answers C and D are correct, however, answer D makes more sense.
Answer:
No, viruses are not considered cells as they're parasitic and can't live on their own. A virus has to infect living cells in order to survive, so it's not considered a cell.
Answer:
Nitrogen is a naturally occurring element that is essential for growth and reproduction in both plants and animals. It is found in amino acids that make up proteins, in nucleic acids, that comprise the hereditary material and life's blueprint for all cells, and in many other organic and inorganic compounds.
Explanation:
(I just copy and paste from google)
Answer:
A portion of the Earth's atmosphere that protects the Earth from radiation
