The correct answer is A. Norethindrone.
Norethindrone is a progestin, a type of hormone that helps to regulate the menstrual cycle. It is also used as a “morning after pill” to prevent pregnancy after unprotected sex. Norethindrone works by preventing ovulation, the release of an egg from the ovary. It can also thicken the cervical mucus, making it more difficult for sperm to reach the egg.
Ethinylestradiol is an estrogen, a type of hormone that helps to regulate the menstrual cycle. It is also used in combination with progestins to prevent pregnancy. Ethinylestradiol works by preventing ovulation and thickening the cervical mucus.
Mifepristone is a medication that is used to end a pregnancy. It is also known as RU-486. Mifepristone works by blocking the effects of progesterone, a hormone that is necessary for pregnancy to continue.
Bithional is a medication that is used to treat parasitic infections. It is not used as a “morning after pill.”
Here is a table that summarizes the information about each option:
| Option | Description |
|—|—|
| A. Norethindrone | A progestin, a type of hormone that helps to regulate the menstrual cycle. It is also used as a “morning after pill” to prevent pregnancy after unprotected sex. Norethindrone works by preventing ovulation, the release of an egg from the ovary. It can also thicken the cervical mucus, making it more difficult for sperm to reach the egg. |
| B. Ethinylestradiol | An estrogen, a type of hormone that helps to regulate the menstrual cycle. It is also used in combination with progestins to prevent pregnancy. Ethinylestradiol works by preventing ovulation and thickening the cervical mucus. |
| C. Mifepristone | A medication that is used to end a pregnancy. It is also known as RU-486. Mifepristone works by blocking the effects of progesterone, a hormone that is necessary for pregnancy to continue. |
| D. Bithional | A medication that is used to treat parasitic infections. It is not used as a “morning after pill.” |