Answer: I would say its C.
Explanation: An atom is the smallest unit of matter that retains all of the chemical properties of ... Some elements follow the English term for the element, such as C for carbon and ... Gold atoms cannot be broken down into anything smaller while still retaining ... only about 1/1800 of an atomic mass unit, so they do not contribute much to ...
Hope its helps please give brainliest!
Metabolism, respiration and digestion are all complex chemical processes involving many steps, happening in 3 dimensional space within cells. Metabolism is the breaking of bonds within food molecules (like sugar) to harness energy for cellular work; respiration involves moving oxygen and carbon dioxide gases between cells to facilitate cellular metabolism and digestion involves breaking down food macro structures into smaller units suitable for metabolism.
So the answer is D - each of the three process involve multiple chemical reactions.