Olympic sprinters undergo increased heart and breathing rates while competing. Which of the following best describes the interactions among systems of a sprinter?

A. Respiratory system is working to obtain more oxygen, while the circulatory system works to transport the oxygen to the muscles.

B. The digestive system takes in more glucose, while the excretory system removes waste.

C. The endocrine system transports ATP to the nervous system

D. Excretory system removes waste from the digestive system to reduce weight so the sprinter can run faster