Compared to Healthy People Who Live at Sea Level,arterial $P _ { o _ { 2 } }$

Compared to healthy people who live at sea level,arterial $P _ { o _ { 2 } }$ is lower in people who

A) Live at high altitude
B) Have pulmonary edema
C) Have iron-deficiency anemia
D) Both live at high altitude and have pulmonary edema are correct
E) All of the choices are correct