Most important antigen initiating graft rejection: (A) MHC - molecule, (B) Polysaccharide, (C) DHA, (D) HLA - Antigen
Answer is D. the most important consequence of direct recognition is the activation of CD8+ T cells 
which recognise class I MHC molecules in the graft.Host CD4+ helper T cell may be triggered into proliferation and cytokine production by recognition of donor
class II MHC molecules  and drive an inflammatory response