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
Graham Cole test refers to - 
Select and explain. 
A. Oral cholecystography, B. Intravenous cholangiography, C. Pre-operative cholangiography, D. Post-operative cholangiography
A: Oral cholecystography
Answer: A: Oral cholecystography 
Explanation: None