Scientific knowledge becomes stronger and more durable as a result of

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

When a human or animal consumes food, the carbon in that food is most likely to be converted into which of the following elements? a. carbon remains carbon b. nitrogen c. oxygen d. hydrogen

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above