**Core Concept**
Long-acting reversible contraceptives (LARCs) are a class of birth control methods that provide effective contraception for an extended period, typically lasting several years or even a lifetime. These methods are characterized by their ability to be easily reversible, allowing users to regain fertility once the contraceptive is removed.

**Why the Correct Answer is Right**
The correct answer is **Implantable Contraceptive Device (Implanon)**, also known as Nexplanon. This device releases etonogestrel, a progestin, which suppresses ovulation and thickens cervical mucus to prevent fertilization. The etonogestrel implant is effective for up to 3 years and is a popular LARC option due to its high efficacy and ease of use.

**Why Each Wrong Option is Incorrect**
**Option A:** Copper Intrauterine Device (Cu-IUD) is a type of LARC that works by releasing ions that are toxic to sperm, thereby preventing fertilization. It is effective for up to 10 years and is a popular option for those who cannot use hormonal contraceptives.

**Option B:** Progestin-releasing Intrauterine System (Mirena) is a type of LARC that releases levonorgestrel, a progestin, which suppresses ovulation and thickens cervical mucus to prevent fertilization. It is effective for up to 5 years and is a popular option for those who want to manage heavy menstrual bleeding.

**Option C:** Depo-Medroxyprogesterone Acetate (DMPA) is a type of injectable contraceptive that releases medroxyprogesterone acetate, a progestin, which suppresses ovulation and thickens cervical mucus to prevent fertilization. It is effective for up to 12 weeks and is a popular option for those who prefer a non-invasive method.

**Clinical Pearl / High-Yield Fact**
LARCs are highly effective in preventing unintended pregnancies, with a failure rate of less than 1%. They are also a popular option for those who want to delay childbearing or have not yet achieved their desired family size.

**Correct Answer:** D.