This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
Dye used in IV cholangiography is 
Select and explain. 
A. Conray, B. Diansoil, C. Biligraffin, D. Myodil
C: Biligraffin
Answer: C: Biligraffin 
Explanation: Iponoic acid is used in oral cholecystography Biligraffin is used in IV cholangiography Ref: Sabiston 20th edition Pgno :1487