The heart is the primary organ, which pumps blood through the body. The heart automatically adjusts the blood flow to match the activity levels by the intake of more oxygen.
The heart functions appropriately in the presence of oxygen. During a time of activity or an exercise, the body requires an extra amount of energy to meet the needs of the activity. The heart adjusts itself by taking up more oxygen so that the blood flow is increased and the oxygen demand is met.
The heart pumps necessary blood volume to different parts of the body such that, the body does not suffer from any physiological problems.
Thus, the heart sets the blood flow by taking up more oxygen. The correct answer is Option B.
To know more about heart, refer to the following link:
https://brainly.com/question/7126207
The correct answer is A!
~Hope this helps!
(sorry if I'm wrong although I shouldn't be)
