Answer:
D. deliver oxygen to every blood cell
Explanation:
Respiration is the process by which organisms liberate energy from food by chemical processes. It is more appropriately called cellular respiration as the process occurs in the cell.
During respiration, energy is released from food when oxygen combines with food materials. The waste product is carbondioxide in most cases.
The ultimate purpose of respiration(breathing) is to furnish the body system with oxygen at cellular level for the release of energy.
