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
Cholangiocarcinoma has been associated with infection by 
Select and explain. 
A. Paragonimus westermani, B. Clonorchis sinensis, C. Loa Loa, D. Schistosoma haematobium
B: Clonorchis sinensis
Answer: B: Clonorchis sinensis 
Explanation: Risk factors for cholangiocarcinoma Choledochal cyst Primary sclerosing cholangitis Ulcerative colitis. RPC or hepatolithiasis. Biliary enteric anastomosis HBV, HIV, HCV Choledocholithiasis Clonorchis sinensis and opisthorchis viverrini Cirrhosis Radon Asbestos, Nitrosamines, Dioxib(AND). Diabetes, Obesity, OCP's, smoking, Thorotrast, Isoniazid(DOSTI) Ref: Sabiston 20th edition Pgno :1514