Which of the following options is not a method of emergency contraception to be administered within 72 hours of unprotected sexual activity?
Combination pill
IUD
High dosage of progesterone
High dosage of estrogen
A high dosage of estrogen is not a method of emergency contraception to be administered within 72 hours of unprotected sexual activity. Emergency contraception typically involves the use of progestin-only pills, also known as the "morning-after pill," or the insertion of an intrauterine device (IUD). These methods are effective in preventing pregnancy after unprotected intercourse. While some emergency contraceptive pills may contain a combination of estrogen and progestin, a high dosage of estrogen alone is not commonly used as an emergency contraception method. Hence, the correct answer is option 4.