This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of Thyroid, Subject name: Medicine
[{'content': 'Which of the following is associated with AV block? \nSelect and explain. \nA. Hypothyroidism, B. Hypehyroidism, C. Cushing disease, D. Pheochromocytoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Metabolic /endocrine causes of Atrioventricular Block 1. Hyperkalemia 2. Hypermagnesemia 3. Adrenal insufficiency 4. Hypothyroidism', 'role': 'assistant'}]