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: Microbiology
Which of the following may cause a biliary obstruction - 
Select and explain. 
A. Ancylostoma, B. Enterobius, C. Strongyloides, D. Clonorchis
D: Clonorchis
Answer: D: Clonorchis 
Explanation: None