Which of the following demonstrates a compensation that makes the ventilation to perfusion ratio more ideal?
a) Vasoconstriction in arteries that perfuse a well-ventilated set of alveoli
b) Constricting airways that ventilate a well-perfused region of lung
c) Vasodilating in the bottom of a lung in an individual at rest
d) Relaxing smooth muscle in walls of airways in the bottom of the lung of an individual at rest
