This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
[{'content': 'Causes of Vit. B12 deficiency megaloblastic anemia- \nSelect and explain. \nA. Fish tap worm infestation, B. Dilantin therapy, C. Gastrectomy, D. Ileal resection', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Fish tapeworm competes with cells in the ilium for vitamine B12 there by causing its defficiencyin the body. Reference:Exam preparatory manual for UGs by Ramdas Nayak Page no.:256', 'role': 'assistant'}]