Nessesary concept related to drugs

Does anyone have an answer to this question? if so me.

Arm circles are often effective dynamic stretches for swimmers because they

The amount of oxygen that is actually used by the body during the rest or a hand workout is determined by the heart rate, the stroke volume, and the amount of a. blood circulating in the vascular system b. oxygen removed from the vascular system c. oxygen provided to the vascular system d. blood that individual has in the body e. hemoglobin in the red blood cells