<prompt> Most immunogenic RBC blood group system out of the given options is:-KellDuffyKiddLewis antigen  <response>: Most immunogenic RBC blood group system:- ABO Blood Grouping Rh Kell. If there is mismatch bw two individual on differential expression of the Kell ag, this can be responsible for Hemolytic diseases of new born HDN Duffy ReceptorAg on RBC which facilitate the entry of plasmodium vivax. Therefore, those individual with Duffy negative RBC are resistant to plasmodium vivax Malaria. 