This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hepatobiliary radiology, Subject name: Radiology
[{'content': 'Parallel shotgun appearance on Ultrasound is seen in \nSelect and explain. \nA. Poal hypeension, B. Biliary ascariasis, C. Obstructive jaundice, D. Sclerosing cholangitis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Distal CBD obstruction: Common bile duct gets distended due to obstruction & gives a "Double Barrel appearance" or "Parallel Shotgun sign" on USG', 'role': 'assistant'}]