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
Gallbladder adenocarcinoma involving lamina propria and muscular layer. What is the preferred treatment 
Select and explain. 
A. Simple cholecystectomy, B. Radical cholecystectomy, C. Chemotherapy, D. Radiotherapy
B: Radical cholecystectomy
Answer: B: Radical cholecystectomy 
Explanation: Radical cholecystectomy -removing gallbladder+liver segments 4b and 5+lymph nodes along hepatoduodenal ligament.