This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Hypersensitivity pneumonitis is classically a/an 
Select and explain. 
A. Allergic reaction, B. Type II hypersensitivity, C. Immune complex mediated hypersensitivity, D. Cell mediated hypersensitivity
C: Immune complex mediated hypersensitivity
Answer: C: Immune complex mediated hypersensitivity 
Explanation: Hypersensitivity pneumonitis Allergic alveolitis TYPE III +TYPE IV HS Complement & Ig in the vessel walls - Type III Non-caseating granulomas in 2/3rd patients - Type IV