Fertility is impaired when a male's sperm count drops below ____ sperm per milliliter of semen, and the male is considered sterile if his sperm count drops below ____ sperm per milliliter of semen.
A) 500 million; 200 million
B) 100 million; 50 million
C) 35 million; 20 million
D) 2 million; 1 million
E) 500,000; 100,000