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 used in hepatitis B infection is - \nSelect and explain. \nA. Entecavir, B. Astacavir, C. Zanamivir, D. Abacavir', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Entecavir o Entecavir is the DOC for chronic hepatitis B infection.", 'role': 'assistant'}]