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: Surgery
[{'content': 'Gallbladder adenocarcinoma involving lamina propria and muscular layer. What is the preferred treatment \nSelect and explain. \nA. Simple cholecystectomy, B. Radical cholecystectomy, C. Chemotherapy, D. Radiotherapy', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Radical cholecystectomy -removing gallbladder+liver segments 4b and 5+lymph nodes along hepatoduodenal ligament.', 'role': 'assistant'}]