**Core Concept**
G6PD deficiency is a genetic disorder characterized by a deficiency of the enzyme glucose-6-phosphate dehydrogenase. This enzyme plays a crucial role in protecting red blood cells from oxidative damage. Patients with G6PD deficiency are prone to hemolysis when exposed to certain medications or substances that can trigger oxidative stress.

**Why the Correct Answer is Right**
The correct answer is a medication that can induce oxidative stress, leading to hemolysis in individuals with G6PD deficiency. **Primaquine** is a well-known antimalarial drug that can trigger hemolysis in patients with G6PD deficiency. This is because primaquine can generate reactive oxygen species, which can damage red blood cells and lead to hemolysis.

**Why Each Wrong Option is Incorrect**
**Option A:** **Chloroquine** is not a correct answer because, although it can also have hemolytic effects, it is not as strongly associated with G6PD deficiency as primaquine. **Option B:** **Ciprofloxacin** is not a correct answer because it is an antibiotic that can cause other side effects, but it is not typically associated with hemolysis in G6PD deficiency. **Option C:** **Aspirin** is not a correct answer because it is not commonly associated with hemolysis in G6PD deficiency.

**Clinical Pearl / High-Yield Fact**
When prescribing medications to patients with G6PD deficiency, it is essential to choose alternatives that are less likely to cause oxidative stress. A mnemonic to remember common medications that can trigger hemolysis in G6PD deficiency is "PQ" for primaquine and "Fava" beans, which can also cause hemolysis in susceptible individuals.

**Correct Answer: D. Primaquine**