During vigorous aerobic exercise in a healthy person, which of the following physiological responses is most likely to occur?

Introduction / Context:
When a person performs vigorous exercise such as running or fast cycling, the body makes several automatic adjustments to meet the increased demand for oxygen and nutrients in the working muscles. Understanding how blood flow is redistributed during exercise is a key part of human physiology and sports science. This question asks you to identify which of the listed responses is most likely in a healthy person who is engaging in vigorous exercise.

Given Data / Assumptions:
- The person is healthy and performing vigorous aerobic exercise, not experiencing shock or serious illness.
- The cardiovascular and respiratory systems respond normally to increased activity.
- The body prioritizes blood flow to active muscles and the skin, and reduces flow to some internal organs during intense exercise.
- We consider typical acute responses during the exercise, not long term training adaptations.

Concept / Approach:
During vigorous exercise, cardiac output increases and blood is redistributed toward active skeletal muscles, the heart, and the skin. Capillaries in the working muscles dilate so that more blood can flow through them, supplying oxygen and removing carbon dioxide and metabolic wastes. Blood flow to the kidneys and digestive organs decreases temporarily, because these organs can function with reduced flow during short periods of activity. The skin typically becomes warm and may sweat to help dissipate heat. Therefore, the correct answer should describe increased blood flow to active muscles, not to kidneys or digestive organs, and should not suggest a decrease in heart rate or cold, clammy skin typical of shock.

Step-by-Step Solution:
Step 1: Identify that vigorous exercise demands more oxygen and nutrient delivery to working muscles. Step 2: Evaluate option A, which claims blood flow to the kidneys increases, but in reality kidney blood flow usually decreases during intense exercise. Step 3: Evaluate option B, which states that capillaries of the active muscles will be engorged with blood; this fits the need for enhanced oxygen delivery and waste removal during exercise. Step 4: Evaluate option C, which suggests the skin will be cold and clammy; this is typical of shock, not healthy exercise, where the skin tends to be warm and sweaty. Step 5: Evaluate option D, which says blood will be diverted to the digestive organs, but during exercise blood is actually diverted away from digestion to muscles. Step 6: Evaluate option E, which states heart rate will decrease significantly; in vigorous exercise, heart rate increases to pump more blood. Step 7: Conclude that option B correctly describes the physiological response.

Verification / Alternative check:
You can verify this by recalling personal experience of exercise or observing athletes. During heavy activity, muscles feel fuller and warmer because more blood is flowing through them. At the same time, digestion slows, and you may notice that eating a large meal just before intense exercise can cause discomfort, reflecting reduced blood flow to the digestive system. The pulse becomes stronger and faster, not slower, and the skin often becomes flushed and sweaty rather than cold. These observations support the idea that capillaries in active muscles are engorged with blood during vigorous exercise.

Why Other Options Are Wrong:
Blood flow to the kidneys increases, option A, is incorrect because kidney blood flow is often reduced during intense exercise to prioritize muscles and essential organs like the heart.
The skin will be cold and clammy, option C, is characteristic of circulatory shock or severe illness, not normal exercise, where the skin helps lose heat and usually feels warm.
Blood diverted to the digestive organs, option D, is the opposite of what happens; during exercise, blood is diverted away from digestion toward working muscles.
Heart rate will decrease significantly, option E, contradicts the normal response in which heart rate rises to increase cardiac output and meet metabolic demands.

Common Pitfalls:
Some learners may mistakenly associate sweating with feeling cold and clammy and choose that option without considering that healthy exercisers normally feel warm. Others may assume that all vital organs receive increased blood flow during exercise, forgetting that some systems like digestion and kidney function can temporarily operate with less. It is important to remember that the body prioritizes active muscles and thermal regulation during intense activity, which guides you to the correct choice.

Final Answer:
Capillaries of the active muscles will be engorged with blood is the response most likely to occur during vigorous exercise in a healthy person.