Answer:
C. Systemic arterioles respond to a decrease in POâ‚‚ by dilating, but pulmonary arterioles constrict in response to decreased POâ‚‚.
Explanation:
In the arterioles, vasoconstriction is a response to high oxygen while vasodilation is a response to carbon dioxide and low pH. However, in the pulmonary arterioles, vasoconstriction occurs as a response to low oxygen and this mechanism is called hypoxic pulmonary vasoconstriction (HPV).