When an Animal Respires,the Carbon in the Carbon Dioxide That

When an animal respires,the carbon in the carbon dioxide that it breathes out comes indirectly from

A) the air that the organism breaths in.
B) dead and decaying plant matter.
C) fossil fuels.
D) photosynthesis.
E) carbon fixation. When plants photosynthesize, they take carbon dioxide from the atmosphere and build organic molecules such as glucose. When an animal eats either plants or animals, the carbohydrates are broken down and carbon dioxide is released as a waste product. These carbohydrates were originally produced via photosynthesis by producers.