This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Pathology
Earliest feature of TB:- 
Select and explain. 
A. Granuloma, B. Langerhan's Giant cells, C. Lymphocytosis, D. Caseation
C: Lymphocytosis
Answer: C: Lymphocytosis 
Explanation: (C.) - Ingestion of mycobacterium tuberculosis inside the lung will cause stimulation in the no. of lymphocytes, that will cause lymphocytosis First cell in the lung which will be affected by myco. TB infection is alveolar macrophage Transmission of myco. TB - cough & sneeze (droplet infection) (A.) - TB infection is characterized by type 4 hypersensitivity reaction Type 4 hypersensitivity reaction- granuloma formation - LANGHAN's CELL (B.) - Langerhan's cell - giant cell found in the skin. (D.) - type of necrosis seen in TB is CASEOUS NECROSIS.