B. Macromolecules is the answer.
Exercise or any other physical activity, increases the oxygen demand in the lungs and affects the flow of air into the lungs.
Tidal Volume: The amount of air inspired (air that leaves or enters the lungs) during breathing is called tidal volume. With the increase in physical activity such as exercise, the tidal volume increases to allow more gaseous exchange. During exercise, the amount of air to be inhaled increases, thus the tidal volume also increases.
Alveolar Ventilation: It is also known as alveolar volume. It is the amount of air that enters the alveoli in one minute. Alveolar ventilation also increases with the increase in the vital volume due to exercise. This is because oxygen demand increases during exercise.
Anatomical Dead Space: It refers to the air that is directed towards the alveoli but does not participate in the gaseous exchange It decreases during exercise due to increase in ventilation.
Answer:
I think it's A) A protein substrate
