Correct answer is option E
Class III MHC genes have immune related functions. These genes encode for some complement proteins, cytokines and heat shock proteins. The MHC class III genes have the highest gene density but some of the genes are not involve in the immune systems.
Class I MHC molecules are found on all nucleated cells in the body and the bind to CD 8+ T cells. The MHC I gene encodes for CD 8+ T cells.
Class II MHC molecules are found on antigen presenting cells, macrophages, dendritic cells and B cells. These cells bind to CD 4+ T cells. The MHC II gene encodes for CD4+ T cells.