Question

which reason best explains why living things need carbon? carbon bonds are a source of energy. carbon levels reduce global temperatures. carbon acts as an important solvent. carbon is everywhere.

Explanation:

Living organisms break carbon - containing compounds through metabolism to release energy. Carbon bonds store chemical energy. Carbon levels actually contribute to global warming rather than reducing it. Carbon is not a common solvent. Just being everywhere does not explain why living things need it.

Answer:

Carbon bonds are a source of energy.