Which of the Following Changes Occurs During Strenuous Exercise?
A) $\mathrm{O}_{2}$

Which of the following changes occurs during strenuous exercise?

A) Ventilation rate and $\mathrm{O}_{2}$ consumption increase to the same extent
B) Systemic arterial $\mathrm{Po}_{2}$ decreases to about $70 \mathrm{~mm} \mathrm{Hg}$
C) Systemic arterial $\mathrm{PCO}_{2}$ increases to about $60 \mathrm{~mm} \mathrm{Hg}$
D) Systemic venous $\mathrm{PCO}_{2}$ decreases to about $20 \mathrm{~mm} \mathrm{Hg}$
E) Pulmonary blood flow decreases at the expense of systemic blood flow