Answer:
C
Explanation:\
The rest make no sense or would hurt him more.
I think that oxygen is needed , because it helps elevate the blood level and help oxygen spread to your brain/ heart.
Answer:
essential
Explanation: Amino acids are organic compounds composed of nitrogen, carbon, hydrogen and oxygen, along with a variable side chain group. Your body needs 20 different amino acids to grow and function properly. Though all 20 of these are important for your health, only nine amino acids are classified as essential