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 investigation of choice for acute cholecystitis is – 
Select and explain. 
A. USG, B. HIDA-Scan, C. CT-Scan, D. X-ray
A: USG
Answer: A: USG 
Explanation: Investigation of choice for acute cholecystitis   → USG
Most accurate (best) method for diagnosis of acute cholecystitis → Radionuclide scan (DISIDA, PIPIDA, HIDA)