This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'True about MHC - \nSelect and explain. \nA. Present on chromosome 4, B. Class II compromises A, B, C loci, C. Class III has complement, D. Class I is involved in mixed leucocyte reaction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: MHC class III genes encode several components of the complement system (i.e. C2, C4a, C4b, Bf), they are responsible for the levels of components of compliment system. Reff: Ananthanarayan & Panikers textbook of microbiology 9th edition pg: 140', 'role': 'assistant'}]