This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
The drug with definite risk of hemolysis in patients with G6PD deficiency is: 
Select and explain. 
A. Cotrimoxazole, B. Chloroquine, C. Sulfasalazine, D. Quinine
A: Cotrimoxazole
Answer: A: Cotrimoxazole 
Explanation: All the choices have risk of clinical hemolysis in G6PD. Definite risk is seen with Cotrimoxazole only, Others have either possible or doubtful risk. Ref: Harrison 18th edition, Page 879.