All Animals Undergoing Cellular Respiration Must Get Rid of CO₂

All animals undergoing cellular respiration must get rid of CO₂ because

A) as CO₂ increases,it interferes with lung function.
B) as CO₂ increases,it makes body fluids more acidic.
C) as CO₂ increases,it decreases brain function.
D) as CO₂ increases,it is less able to be stored as sugar.
E) CO₂ is incredibly toxic.