**Core Concept**
Transvestism is a psychological condition where an individual derives pleasure or satisfaction from dressing in the attire of the opposite sex. This behavior is often associated with a desire to express oneself in a way that is not traditionally aligned with one's biological sex.

**Why the Correct Answer is Right**
Transvestism, also known as transvestic fetishism, is a type of paraphilia characterized by a recurring and intense sexual arousal from dressing in the attire of the opposite sex. This behavior is often seen in individuals with a gender identity disorder, where the individual's perception of their own gender does not match their biological sex. The act of dressing in the opposite sex's attire can serve as a means of self-expression, relaxation, or even as a way to cope with stress.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not refer to the condition of dressing in the attire of the opposite sex for sexual gratification.
**Option B:** This option is incorrect as it is a different psychological condition altogether, characterized by a fear of being in public places or situations where escape might be difficult.
**Option C:** This option is incorrect as it refers to a different type of paraphilia, characterized by a recurring and intense sexual arousal from non-human objects or animals.

**Clinical Pearl / High-Yield Fact**
It's essential to note that transvestism is not the same as cross-dressing, which can be a fashion choice or a form of self-expression without any underlying psychological condition.

**Correct Answer: C. Transvestic fetishism.