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: Pathology
Cholangio carcinoma of liver caused by - 
Select and explain. 
A. Hepatitis B infection, B. Cirrhosis of liver, C. Alpha - feto protein, D. Clonorchis - sinensis infection
D: Clonorchis - sinensis infection
Answer: D: Clonorchis - sinensis infection 
Explanation: None