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: Medicine
[{'content': 'Megaloblastic anemia due to folic acid deficiency is commonly due to - \nSelect and explain. \nA. Inadequate dietary intake, B. Defective intestinal absorption, C. Absence of folic acid binding protein in serum, D. Absence of glutamic acid in the intestine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]