**Core Concept**
Eugenics is a discredited and pseudoscientific theory that aims to improve the human species through selective breeding and genetic engineering, often targeting certain racial, ethnic, or socioeconomic groups. This concept is rooted in the idea of "survival of the fittest" and the notion that certain individuals or groups are superior to others. However, eugenics has been widely criticized for its association with Nazi atrocities and its disregard for human rights and dignity.

**Why the Correct Answer is Right**
The concept of eugenics gained popularity in the early 20th century, particularly in the United States and Europe, where it was used to justify forced sterilization and other coercive measures aimed at "improving" the human gene pool. **Eugenics programs** were often linked to **eugenic sterilization laws**, which allowed for the forced sterilization of individuals deemed "unfit" or "undesirable." The ideology of eugenics was rooted in the **social Darwinism** movement, which applied the principles of natural selection to human societies.

**Why Each Wrong Option is Incorrect**
* **Option A:** Eugenics is a form of medical ethics. **Incorrect**, as eugenics is actually a discredited and pseudoscientific theory that violates medical ethics and human rights.
* **Option B:** Eugenics is a form of population control. **Incorrect**, as while eugenics does involve controlling the reproductive capabilities of certain individuals or groups, its primary goal is to "improve" the human species through selective breeding.
* **Option C:** Eugenics is a form of genetic engineering. **Incorrect**, as while eugenics does involve genetic engineering, its scope and goals are much broader and more sinister.

**Clinical Pearl / High-Yield Fact**
It's essential to recognize the historical and ongoing risks of eugenics, including forced sterilization, coercive reproductive practices, and the stigmatization of marginalized groups. The field of genetics has made significant progress in recent years, but it's crucial to approach genetic research and applications with caution and respect for human rights and dignity.

**Correct Answer: D.