Answer:
B. depends on the ability to reliably predict the time of ovulation, every month for the entire duration of time during which a woman does not wish to become pregnant.
Explanation:
The rhythm method of birth control -
It is one of the birth control method , with an average of 80 and 87 percent effective for the prevention of the chances of pregnancy .
Since , not every day of the month is equally fertile to get pregnant .
Hence ,
This method , depends on the ovulation period of the women , as during the ovulation period , the women is more expected to get pregnant , if the egg get fertilized .
Therefore , the women can get pregnant with the egg is fertilized during the ovulation period , but the chances of pregnancy apart from the ovulation period is very low.
