## **Core Concept**
The question tests the knowledge of side effects associated with long-term use of antipsychotic medications, specifically the risk of retinal pigmentation. This is a known side effect of certain antipsychotics.

## **Why the Correct Answer is Right**
The correct answer, , is associated with a higher risk of retinal pigmentation. This side effect is particularly noted with the use of **thioridazine**, a first-generation (typical) antipsychotic. Thioridazine is known to cause **retinal toxicity** and **pigmentary retinopathy**, especially at higher doses or with prolonged use. The mechanism involves the deposition of lipofuscin in the retinal pigment epithelium.

## **Why Each Wrong Option is Incorrect**
- **Option A:** is not commonly associated with retinal pigmentation to the extent that thioridazine is.
- **Option B:** does not have a significant association with retinal pigmentation compared to thioridazine.
- **Option D:** is not particularly known for causing retinal pigmentation.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that **thioridazine** is notorious for its risk of **retinal toxicity**, which can lead to vision problems. This side effect necessitates regular ophthalmologic examinations in patients on long-term thioridazine therapy.

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