This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: parasitology, Subject name: Microbiology
[{'content': 'Which of the following does not cause biliary tract obstruction ? \nSelect and explain. \nA. Ascaris lumbricoides, B. Ankylostoma duodenale, C. Clonorchis sinensis, D. Fasciola hepatia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Pathogenesis and clinical features of ankylostoma duodanale Infective agent: filariform larvae Poal of entry: skin The worm causes hookworm disease in man characterized mainly by anaemia. (refer pgno:144 baveja 3 rd edition)', 'role': 'assistant'}]