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: Psychiatry
[{'content': "Most common cause of death in Rett's syndrome is \nSelect and explain. \nA. Hypoglycemia, B. Cardiac arrhythmias, C. Seizures, D. Respiratory failure", 'role': 'user'}, {'content': "Answer: B \nExplanation: Cardiac arrythmia\xa0is the leading cause of death in Rett's syndrome.", 'role': 'assistant'}]