Although more than 400 blood groups have been identified,the ABO blood group system remians the mostimpoant in clinical medicne because :: (A) It was the first blood group system to be discovered, (B) It has four different blood groups A,B, AB, O (H)., (C) ABO(H) antigens are present in most body tissues and fluids., (D) ABO(H) antibodies are invariably present in plasma when persons RBC lacks the corresponding antigen
Answer is D. . ABO(H) antibodies are invariably present in plasma when persons RBC lacks the corresponding antigen