Abigail, a 23-year-old woman, gave birth to a baby girl a month ago but has not experienced her first postpartum menses. She does not want to use hormonal methods of contraception as she fears that it will interfere with her milk production. Instead, she breastfeeds her baby every 5 hours during the day and every 6 hours at night and successfully avoids getting pregnant. Which of the following methods of contraception is used by Abigail in this scenario?

A) the basal body temperature method
B) the lactational amenorrhea method
C) the calendar (rhythm) method
D) the symptothermal method

Abigail is practicing the lactational amenorrhea method, which is a natural form of contraception that relies on the frequency and intensity of breastfeeding to suppress ovulation, thereby delaying the return of menstrual cycles. This method can be effective for up to six months postpartum, provided that certain conditions are met, such as exclusive breastfeeding and frequent feedings around the clock. It does not require any external devices or medications and is safe for both the mother and the baby. However, it is not a reliable long-term method and should be supplemented with other forms of contraception once breastfeeding decreases or stops.