Final answer:
The student's question pertains to a reusable silicone barrier vaginal contraceptive with a one-way valve, which is a Cervical cap. This contraceptive is designed to physically block sperm from entering the uterus when placed over the cervix.
Step-by-step explanation:
The correct answer to the question is A) Cervical cap. A cervical cap is a reusable silicone barrier vaginal contraceptive that is used to prevent pregnancy. It is a small cup made of silicone that fits over the cervix and has a one-way valve designed to create a suction and prevent sperm from entering the uterus. Unlike a diaphragm, the cervical cap does not cover the entire vaginal canal but rather sits directly over the cervix, acting as a physical barrier against sperm. It can be used in combination with spermicide for increased effectiveness. The cervical cap should be inserted before intercourse and can be left in place for up to 48 hours, offering continuous protection against pregnancy during that time. It is important to be properly sized by a healthcare provider for a cervical cap to ensure that it fits correctly and works effectively.