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
Dye used in IV cholangiography is ? 
Select and explain. 
A. Di an soil, B. Conray, C. Biligraffin, D. Myodil
C: Biligraffin
Answer: C: Biligraffin 
Explanation: Ans. is 'c' i.e. Biligraffin