This element is found in all living things. It is recycled when organisms die. It is transformed from one form to another through photosynthesis and cellular respiration. That element is A) carbon. B) hydrogen. C) nitrogen. D) oxygen.

Carbon is the backbone of life in all living things. It plays an incredibly important role in protein structure and function and is incredibly important. Without carbon, we couldn't exist.

Hydrogen does not play an important role in life (to the same extent)

Oxygen is nearly as important

Nitrogen is apart of proteins especially :)

Explanation:

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.