Analyze and answer the following case-based scenario:
In a school awareness program, students learned that artificial contraceptive methods such as IUDs, hormonal methods and barrier methods help prevent unwanted pregnancy. These methods are chosen based on safety, convenience and effectiveness.
a. Copper-T belongs to which category of contraceptive methods?
b. Which of the following is a feature of artificial contraceptive methods?
c. Hormonal methods work mainly by ________.
d. Which of the following is not an artificial method of contraception?