You are working in a busy OB/GYN office, and the last patient of the day is P.B., a 36-year-old who is planning to get married soon. She wants to use birth control but is not sure what to choose. Her fianc is in law school, and they do not have health insurance, so she is anxious not to get pregnant right away. She asks you to review the various methods and help her explore what is best for her. P.B. asks you about the effectiveness rating of available birth control methods. Categorize your response according to the following efficacy ratings: most effective (more than 99%), highly effective (97% to 99%), and moderately effective (less than 90%).