Jon is a 200 m sprinter who lives in Mill Spring Hill, Florida (elevation: 131 ft). In preparation for the national championship that will be held in Durango, Colorado (elevation: 6512 ft) in September, Jon moved to Durango in March for daily training. Jon’s hematocrit index in September will be ____ than that in March because Jon’s body has responded to hypoxia by secreting the hormone ______ that ______ RBC production.
a. higher : testosterone : increases
b. higher : erythropoietin : increases
c. lower : cortisol : increases
d. lower : surfactant : decreases
e. higher : GH : increases