This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Nutritional Deficiencies, Subject name: Social & Preventive Medicine
Keshan cardiomegaly occur due to deficiency of:- 
Select and explain. 
A. Selenium, B. Copper, C. Zinc, D. Iron
A: Selenium
Answer: A: Selenium 
Explanation: - Selenium deficiency cause Keshan disease also known as Endemic cardiomyopathy. - There is also involvement of coxsackie virus Other deficiency leads to - Vit A - Xeropthalmia - Vit B1 - Beri - Beri; Wernickes Korsakoff psychosis - Vit B3 - Pellagra - Vit B5 - Burning feet syndrome - Vit B6 - Microcytic neuritis; Peripheral Anemia - B9 - Megalablastic Anemia, Neural tube effect - B12 - Megaloblastic Anemia, Pernicious Anemia, Peripheral Neuritis, Subacute combined degeneration of spinal cord.