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
True about features of cholecystitis on USG : 
Select and explain. 
A. Thick fibrosed gallbladder wall, B. Stone impacted at neck of gall bladder, C. Perigallbladder halo, D. All
D: All
Answer: D: All 
Explanation: A i.e. Thick fibrosed gall bladdar wall; B i.e. Stone impacted at neck of gall bladder; C i.e. Perigall bladdar halo