This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
A45 yr old patient present with history of fever .night sweat ,weight loss. On x Ray a mass in apical love of lung is seen.on histopathology it was found to have caseous nercrosis . What is the likely underlying process involved 
Select and explain. 
A. Enzymatic degeneration, B. Hypersensitivity reaction with modified macrophages, lymphocytes and giant cells, C. Acute decrease in blood supply, D. Decreased supply of growth factor
B: Hypersensitivity reaction with modified macrophages, lymphocytes and giant cells
Answer: B: Hypersensitivity reaction with modified macrophages, lymphocytes and giant cells 
Explanation: Ref Robbins 9/e p272 Presence of history of fever, night sweat and weight loss with apical lesson having caseous necrosis is a pointer to the presence of tuberculosis in the patient.this is characterised by the stimulation of the macrophages to kill mycobacteria.the TH2 response leading to the formation of granuloma is a feature of type 4 hypersensitivity reaction