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 early east African trypanosomiasis : \nSelect and explain. \nA. Pentamidine, B. Suramine, C. Melarsoprol, D. Nifurtimox', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Early east African trypanosomiasis : Suramine\nLate\xa0east African trypanosomiasis : Melarsoprol\nAmerican trypanosomiasis : Benznidazole', 'role': 'assistant'}]