This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Surgery
32-year man presented with fever and pain in upper right hypochondrium after food intake. Investigation of choice; 
Select and explain. 
A. CECT, B. Ultrasound, C. MRI, D. HRCT
B: Ultrasound
Answer: B: Ultrasound 
Explanation: Ultrasound is Investigation of choice for Gall stone Acute cholecystitis Acute acalculous cholecystitis Chronic cholecystitis