A healthy individual at sea level has an arterial partial pressure of oxygen ( PaO2 ) of 100mmHg and an arterial oxygen saturation ( SaO2 ) of 98%. What will most likely happen to PaO2 and SaO2 if this individual ascends to high altitude?
(a) PaO2 will decrease, SaO2 will decrease
b) PaO2 will increase, SaO2 will increase
c) PaO2 will decrease, SaO2 will increase
d) PaO2 will increase, SaO2 will decrease