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
The best method of investigation is case of acute cholecystitis is 
Select and explain. 
A. Ultrasound, B. ERCP, C. OCG, D. Radionuclide imaging
D: Radionuclide imaging
Answer: D: Radionuclide imaging 
Explanation: Radionuclide imaging