This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Adrenal Cortex and Medulla, Subject name: Pathology
The most common cause of Addison's disease is:-- 
Select and explain. 
A. Autoimmune adrenalitis, B. Meningococcal septicemia, C. Malignancy, D. Tuberculosis
A: Autoimmune adrenalitis
Answer: A: Autoimmune adrenalitis 
Explanation: Ans. is 'a' Autoimmune adrenalitis " In early series, tuberculosis was responsible for 70 to 90% of cases, but the most frequent cause now is idiopathic atrophy, and an autoimmune mechanism is probably responsible". - Harrison, 15/e, P 2098Remember MC cause of Addison's ds* - Autoimmune adrenalitisMC cause of Addison's ds in India* - TB (API, 6/e, p 972)