If a person who has lived for several years in Denver, Colorado, the mile-high city, moves to New Orleans, Louisiana, much of which is below sea level, the following will happen to their hematocrit over time?

a. It will remain about the same; production and destruction of erythrocytes will be balanced.
b. It will slowly increase, as erythropoiesis increases.
c. It will slowly decrease, as erythropolesis declines.