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: Surgery
Which is the investigation to know the functionality of the gallbladder 
Select and explain. 
A. MRCP, B. PTC, C. HIDA scan, D. EUS scan
C: HIDA scan
Answer: C: HIDA scan 
Explanation: Hida scan is used to see function