**Core Concept**
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic disorder that affects the enzyme responsible for maintaining the integrity of red blood cells. Certain antimalarial drugs can trigger oxidative stress, leading to hemolysis in individuals with G6PD deficiency.

**Why the Correct Answer is Right**
Primaquine is a 8-aminoquinoline antimalarial drug that can cause hemolysis in G6PD-deficient individuals. However, its use is contraindicated in such patients. The correct answer is Mefloquine, a quinoline antimalarial drug, which is considered relatively safe in G6PD-deficient patients due to its lower risk of triggering hemolysis.

**Why Each Wrong Option is Incorrect**
**Option A:** Primaquine - This drug is contraindicated in G6PD-deficient patients due to its high risk of triggering hemolysis.
**Option B:** Chloroquine - While generally safe, chloroquine can cause hemolysis in G6PD-deficient patients, although the risk is lower than with primaquine.
**Option C:** Artemether - This antimalarial drug can cause oxidative stress and potentially trigger hemolysis in G6PD-deficient patients.

**Clinical Pearl / High-Yield Fact**
When treating malaria in a patient with G6PD deficiency, it is essential to choose an antimalarial drug that is relatively safe, such as Mefloquine or Atovaquone-proguanil. Always consider the patient's G6PD status before administering antimalarial drugs.

**Correct Answer:** D. Mefloquine.