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: Pathology
[{'content': "The most common cause of Addison's disease is:~ \nSelect and explain. \nA. Autoimmune adrenalitis, B. Meningococcal septicemia, C. Malignancy, D. Tuberculosis", 'role': 'user'}, {'content': 'Answer: A \nExplanation: . Autoimmune adrenalitis', 'role': 'assistant'}]