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: Pharmacology
[{'content': 'Drug of choice for exo-erythrocystic stage of malaria is ? \nSelect and explain. \nA. Chloroquine, B. Primaquine, C. Proguanil, D. Mefloquine', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Primaquine", 'role': 'assistant'}]