When a person is exercising, the body needs to deliver increased amounts of oxygen to the muscles. which component of blood ensures that the muscles will receive it? thrombocytes leukocytes erythrocytes plasma

The correct answer is erythrocytes. Among all components of the blood, erythrocytes or red blood cells are responsible in delivering oxygen to tissues and carrying carbon dioxide away from tissues.

A person that is exercising will have increase in oxygen demand hence have vasodilation of blood vessels in the muscles causing increase in delivery of blood (and therefore erythrocytes) to ensure adequate oxygen delivery.