A patient comes to the doctor’s office complaining they often feel weak and unable to complete daily tasks like going up and down stairs or sweeping the floor without becoming tired and out of breath. The doctor asks the patient a number of questions and runs several tests to try to determine what is wrong. Which of the following best explains why a patient admitted to the hospital would complain of shortness of breath and extreme fatigue while completing daily activities?

A.

An intestinal parasite is affecting digestion, keeping food from the excretory system when it gets rid of waste.
B.

A heart defect is affecting circulation, keeping the nervous system from sending signals to the body.
C.

A respiratory infection is affecting breathing, keeping oxygen from getting to muscle cells, preventing them from being able to move the body as well.
D.

A pulled muscle is affecting movement, keeping the cardiovascular system from delivering blood to the body.

PLEASE HELP AS FAST AS YOU CAN!!!!! :C