Ovulation is presumed to have occurred if progesterone level is __________ on day 21: (A) 0.3 ng / mL, (B) 3 ng / mL, (C) 30 ng / mL, (D) 300ng / mL
Answer is B. Ovulation can be safely assumed to have occurred if progesterone level exceeds 3 ng / mL on cycle day 21.