The correct option is B Progesterone + Estrogen
'Pills' are tablets containing progesterone alone or progesterone - estrogen combinations. These are oral contraceptives. They act by inhibiting the release of Gonadotropin Releasing Hormone (GnRH) from the hypothalamus. This reduces the amount of Follicle Stimulating Hormone (FSH) & Leutinising Hormone (LH) in blood, thereby, preventing ovulation. Progesterone also makes cervical mucus thick, thereby, reducing the sperm motility and their entry into the fallopian tube.