Which of the following pumps the least amount of blood?

The resting heart rate is the correct answer because it reflects the number of times the heart beats per minute when a person is at rest and not physically active. At rest, the heart operates at a lower intensity, which means it pumps less blood compared to when the body is engaged in exercise or physical activity. This is particularly true as a well-trained athlete often has a lower resting heart rate due to increased efficiency of the cardiovascular system.

During exercise, the heart rate increases to supply more oxygenated blood to the muscles and therefore pumps significantly more blood. The target heart rate and recovery heart rate involve higher levels of exertion and recovery from that exertion, leading to increased blood flow during those times. The pulse measurement also reflects how much blood is being pumped through the arteries, which is typically greater than at rest, particularly during and immediately after physical activity. Thus, the resting heart rate is characterized by the least amount of blood being pumped compared to the other options provided.