Answer:
The correct answer is c. The volume of blood and the number of red blood cells.
VO2max, also known as maximal oxygen uptake, is a measure of the maximum amount of oxygen that an individual can utilize during intense exercise. It is considered one of the most important indicators of aerobic fitness. Several physiological factors contribute to determining VO2max, but the primary factors are related to the delivery and utilization of oxygen by the body.
The volume of blood and the number of red blood cells play a crucial role in determining VO2max. Red blood cells contain hemoglobin, a protein that binds to oxygen in the lungs and transports it to the working muscles. A higher volume of blood and a greater number of red blood cells mean there is a larger capacity to carry and deliver oxygen to the muscles, resulting in a higher VO2max.
Other factors, such as the rate at which the lungs transfer gas into arterial blood (a), the volume of blood the heart pumps each hour (b), the maximum rate at which the lungs can inflate and deflate (d), and the rate at which peripheral tissues produce oxygen (e), also contribute to overall aerobic capacity and exercise performance. However, the volume of blood and the number of red blood cells are the primary physiological factors that determine VO2max.