<prompt> In Erythroblastosis fetalis, the first child is spared because:Immune response in second exposure is fastSensitization of Rh-negative mothers by a Rh-positive fetus generally occurs at bihSmall amounts of fetal blood leak into the ma ternal circulation at the time of deliveryMothers develop significant titers of anti-Rh ag glutinins during the postpaum period  <response>: Sensitization of Rh-negative mothers by a Rh-positive fetus generally occurs at bih 