Which of the following statements regarding contraceptives is incorrect?

A) the rythym method tracks the female menstrual cycle to determine least fertile points in the cycle

B) use of spermicidal products kills or inactivates sperm and any sexually transmitted pathogens to prevent fertilization and disease

C) use of barrier methods prevents entry of sperm into female reproductive tract

D) hormonal oral birth control pills work to prevent ovulation by controlling hormones