**Core Concept**
The question is testing the side effect profile of various medications, specifically their association with corneal microdeposits. Corneal microdeposits refer to the deposition of small particles or substances in the cornea, which can be caused by certain medications.

**Why the Correct Answer is Right**
The correct answer is associated with the mechanism of chloroquine, an antimalarial drug. Chloroquine is known to accumulate in the cornea, leading to the formation of corneal microdeposits. This is due to its lipophilic nature, which allows it to penetrate the cornea and deposit in the epithelial cells.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while other antimalarial drugs may have side effects, they are not commonly associated with corneal microdeposits.
* **Option B:** This option is incorrect because this medication is not typically associated with corneal microdeposits.
* **Option D:** This option is incorrect because this medication is not commonly linked to corneal microdeposits.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that chloroquine can cause corneal toxicity, which can lead to visual disturbances. Regular ophthalmological monitoring is crucial for patients on long-term chloroquine therapy.

**Correct Answer: C. Chloroquine. Chloroquine.**