The Continuation Rate of a Contraceptive Is Determined by the Percentage

The continuation rate of a contraceptive is determined by the percentage of

A) people who keep using a particular contraceptive after a specified period of time.
B) women who cannot become pregnant once they have stopped using a contraceptive.
C) women who become pregnant while using a contraceptive.
D) people who use more than one method of contraception in a single year.