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
The given site encodes 
Select and explain. 
A. Complement component C3, B. Tumor necrosis factor, C. Interleukin-2, D. Beta-2 microglobulin
A: Complement component C3
Answer: A: Complement component C3 
Explanation: MHC class III genes encode*Complement components C2 and C4*Properdin factor B of alternate pathway*TNF - alpha and betaHeat shock proteinsReference: Harrison&;s Principles of Internal Medicine; 19th edition