Which of the following birth control is most effective in sexually active women?
B. Combination birth control pill
C. Vaginal ring
D. Make condom
C. Vaginal ring because it contributes to most gradual and efficient relese of female sex hormones, preventing ovulation and follicle development. The ring is placed into the female reproductive system, ensuring that the concentration of hormones in the target regions will be the most close to the required level.