This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition & Digestion, Subject name: Biochemistry
[{'content': 'Cardiomyopathy is due to deficiency of: \nSelect and explain. \nA. Selenium, B. Phosphorus, C. Boron, D. Zinc', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A. SeleniumNutritional Causes of Cardiomyopathy are:Deficiency of thiamine, selenium, calcium and magnesium.Excess of iron (Hemochromatosis)', 'role': 'assistant'}]