This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'A fisherman presents with C/O chronic diarrhea and fatigue. His physician orders a P/S, which reveals a megaloblastic anemia. Most likely cause is \nSelect and explain. \nA. Clonorchis sinensis, B. D. latum, C. E. granulosus, D. T. saginata', 'role': 'user'}, {'content': 'Answer: B \nExplanation: .', 'role': 'assistant'}]