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': 'Hea block is seen in - \nSelect and explain. \nA. Hypermagensemia, B. Hypomagnesemia, C. Hypernatremia, D. Hypocalcemia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Answer- A. HypermagensemiaHypermagnesemia slows the hea and leads to hea block.', 'role': 'assistant'}]