## Core Concept
Eonism refers to a psychological condition where an individual, typically a male, experiences a strong and persistent desire to live as a female. This concept falls under the broader category of gender dysphoria. The term is derived from the name of the Chevalier d'Eon, a historical figure known for living as a woman.

## Why the Correct Answer is Right
The correct answer, **Transvestism**, is a term used to describe the practice of dressing in a style traditionally associated with the opposite sex. Eonism is indeed another term for transvestism, particularly when it involves a deep-seated desire to live as a member of the opposite sex, not just dressing in their clothes. This behavior is a form of expression of gender identity and can be a part of various gender-related conditions.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is blank and does not provide a viable choice for the question.
- **Option B:** This option is also blank and does not offer a relevant term related to eonism.
- **Option D:** Similarly, this option is blank and does not contribute to understanding the correct term for eonism.

## Clinical Pearl / High-Yield Fact
A key point to remember is that while eonism and transvestism can overlap, eonism historically refers to a more profound identity issue, not just cross-dressing. The term "transvestic fetishism" is used in psychiatric classifications for individuals who have a sexual arousal from cross-dressing, which can be distinguished from eonism.

## Correct Answer Line
**Correct Answer: C. Transvestism**