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': "A child is exclusively fed on cow's milk. the  deficiency seen in \nSelect and explain. \nA. Iron, B. Vitamin A, C. Thiamine, D. Riboflavin", 'role': 'user'}, {'content': "Answer: A \nExplanation: Cow's milk is a poor source of vitamin C and Iron.", 'role': 'assistant'}]