A possible answer could be the quality of air being inhaled
Answer: Exhaled air consists of 78 percent nitrogen, 16 percent oxygen, 4 percent carbon dioxide and potentially thousands of other compounds.
Explanation: Does this help???
Answer: Hope this help, I believe its D
Explanation:
If some living things do not reproduce this could be considered a defect or a genetic mutation in those people. If we take humans for example, if most humans reproduce and some don't because they cannot (if a guy cannot produce sperm) this doesn't mean that he isn't alive, it just means he was born with a genetic mutation which doesn't allow him to produce sperm needed for reproducing.
Probably once and you’ll be sore for a little while