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: Radiology
Most common cause of widening of C loop of duedenum 
Select and explain. 
A. Pancreatitis, B. Carcinoma head of pancreas, C. Choledochal cyst, D. Retroperitoneal masses
B: Carcinoma head of pancreas
Answer: B: Carcinoma head of pancreas 
Explanation: M/c cause - Carcinoma head of pancreas.