One of the Main Reasons That We Exhale a Higher

One of the main reasons that we exhale a higher percentage of carbon dioxide than we inhale is:

A) We use carbon dioxide to make glucose
B) We produce carbon dioxide as a byproduct of aerobic respiration
C) We produce carbon dioxide as a byproduct of transmission of nerve impulses across synapses
D) Carbon dioxide is a byproduct of photosynthesis
E) Carbon dioxide dissolves better in blood than does oxygen