This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmias 1, Subject name: Medicine
[{'content': "All of the following lead to AV block except? \nSelect and explain. \nA. Hypothyroidism, B. Ankylosing spondylitis, C. Lyme disease, D. Lev's disease", 'role': 'user'}, {'content': "Answer: B \nExplanation: Myxedema AV node can block Ankylosing spondylitis will not cause av block Lyme disease caused by Borrelia burgdorferi, transmitted by Tick Bite & causes Myocarditis & AV block. Lev's disease= Idiopathic fibrosis of conduction system.", 'role': 'assistant'}]