**Core Concept**
The Cu-T-380A is a type of intrauterine device (IUD) that contains copper wire. It works by releasing copper ions, which induce a local inflammatory response in the uterus, thereby preventing pregnancy. The mechanism of action involves the release of copper ions, which interfere with sperm motility and ovulation.

**Why the Correct Answer is Right**
The Cu-T-380A is a non-hormonal, long-acting reversible contraceptive (LARC) that is effective for up to 10 years. It is made of flexible plastic and contains 380 mm² of copper wire. The copper ions released by the IUD induce a local inflammatory response, which creates a hostile environment for sperm and fertilization. This mechanism of action is similar to other copper IUDs, such as the Cu-T-220A and the Multiload Cu-375. The Cu-T-380A is a popular choice for women who do not want to use hormonal contraceptives or have failed other methods of contraception.

**Why Each Wrong Option is Incorrect**
**Option A:** The Cu-T-380A is not effective for 5 years, as this is the duration of other copper IUDs like the Cu-T-220A.
**Option B:** The Cu-T-380A does not require replacement every 3 years, as this is the duration of hormonal IUDs like Mirena.
**Option C:** The Cu-T-380A is not made of copper, but rather contains copper wire embedded in a flexible plastic frame.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the Cu-T-380A is a LARC, meaning it is a highly effective form of contraception that can be used for a long period without the need for frequent replacement or refills.

**Correct Answer: D. 10 years**