This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
The most likely cause of bi-hilar lymphadenopathy is 
Select and explain. 
A. Histoplasmosis, B. Tuberculosis, C. Sarcoidosis, D. Aspergillosis
C: Sarcoidosis
Answer: C: Sarcoidosis 
Explanation: SarcoidosisChronic multisystem disorder of unknown cause characterized by the accumulation of TH 1lymphocytes and mononuclear phagocytes in various tissues of the body.Non-caseating sarcoid Granuloma in affected organsLungs (90%)Lymph nodesSkinOthersInterstitial lung disease (fibrosis of lung parenchyma)Pleura is involved, in 1-5% cases unilateral pleural effusion Cavitation is rare B/L hilar lymphadenopathy is the hallmark of Sarcoidosis B/L parotid enlargement Erythema nodosum Lupus pernio(purple-blue shiny swollen lesion on nose, cheeks, lips, ears)UveitisRenal hypercalcemia with or without hypercalciuriaAhritisPeripheral neuropathyCor-pulmonale(Refer: Harrison's Principles of Internal Medicine, 18thedition, pg no: 2805-2813)