The GM progenitor cell gives rise to two main classes of white blood cells in the presence of appropriate colony-stimulating factors. Both of these cell types …

A) have relatively long half-lives, being capable of living for months if not years.
B) circulate in the bloodstream for most of their life-span.
C) are phagocytes.
D) are unaffected by colony-stimulating factors once terminally differentiated.
E) All of the above.