Exercise at high altitudes is hindered by

 A. False Atmospheric drag is reduced at high altitudes.

B. True Due to impaired saturation of the blood with oxygen (hypoxic hypoxia).

C. True Due to increased ventilation induced by hypoxia; this limits ability to further increase ventilation.

D. False This compensates for the low PCO2 and allows increased ventilation.

E. True Lactate levels tend to rise rapidly and fall slowly, leading to intense fatigue and collapse.