Hormonal methods of birth control reduce the risk of pregnancy by releasing hormones that:

Hormonal methods of birth control reduce the risk of pregnancy by releasing hormones that:

• A. block the effects of estrogen, thereby eliminating the fertile period of the menstrual cycle.
• B. increase the acidity of uterine tissue, thus creating an inhospitable environment for sperm.
• C. inhibit the ovaries from releasing eggs and thicken the cervix, making it impenetrable to sperm.
• D. destabilize the membranes of sperm, thereby decreasing their speed and ability to join with an egg.

Answer: (C)

Hormonal birth control works by delivering hormones that disrupt the normal ovulation process and alter the cervical environment. By providing progestin (often with estrogen), these methods suppress the LH surge that triggers ovulation, so no egg is released. At the same time, the hormonal changes thicken cervical mucus, creating a barrier that makes it harder for sperm to travel through the cervix to reach an egg. Some hormonal methods also thin and stabilize the uterine lining, reducing the chance of implantation, but the central effects are preventing ovulation and making sperm penetration more difficult. This combination—inhibiting egg release and thickening the cervical mucus—best reflects how hormonal contraception reduces pregnancy risk.

Hormonal birth control works by delivering hormones that disrupt the normal ovulation process and alter the cervical environment. By providing progestin (often with estrogen), these methods suppress the LH surge that triggers ovulation, so no egg is released. At the same time, the hormonal changes thicken cervical mucus, creating a barrier that makes it harder for sperm to travel through the cervix to reach an egg. Some hormonal methods also thin and stabilize the uterine lining, reducing the chance of implantation, but the central effects are preventing ovulation and making sperm penetration more difficult. This combination—inhibiting egg release and thickening the cervical mucus—best reflects how hormonal contraception reduces pregnancy risk.