Answer:
C
Explanation:
Let's look at the cellular respiration equation
oxygen+glucose--> water + carbon dioxide + ATP
In the process, oxygen is used. We inhale oxygen and use it in cellular respiration. We then create carbon dioxide which is exhaled out. We don't use the carbon dioxide, so it is the waste product.
Therefore, the answer is C. Oxygen is used, and carbon dioxide is released as waste.
