Answer:
a. oral contraceptives
Explanation:
Oral contraceptive are hormonal method of birth control.They are set of medication that prevents pregnancy. Their mode of working is to delayed or prevent ovulation, increases secretion of the mucus lining of the cervix and uterine, so that pregnancy is prevented even if sexual intercourse occurs and ejaculation take place.
They are prepared as combination of synthetic female reproductive hormones oestrogen, progesterone where they inhibit secretions of luteinizing hormone(LH) and follicle stimulating hormone from the anterior pituitary glands(hormones for zygote developments and walls of uterus preparation respectively).
OR progestin(which increases mucus thickness and prevent ovulation)
