Which of the following statements about the response of arteriolar smooth muscle to changing oxygen partial pressures is TRUE?

A)Both systemic and pulmonary arterioles respond to a decrease in PO₂ by constricting.
B)Both systemic and pulmonary arterioles respond to a decrease in PO₂ by dilating.
C)Systemic arterioles respond to a decrease in PO₂ by dilating,but pulmonary arterioles constrict in response to decreased PO₂.
D)Systemic arterioles respond to a decrease in PO₂ by constricting,but pulmonary arterioles dilate in response to decreased PO₂.
E)Changes in PO₂ do not affect arteriolar smooth muscle in the pulmonary system.