Hemolytic transfusion reactions seldom occur because the incidence of unexpected antibodies in random patients is...

Hemolytic transfusion reactions seldom occur because the incidence of unexpected antibodies in random patients is relatively low, e.g., 3-5% is sometimes cited.

Being transfused with O Rh negative RBC is irrelvant if you have an unexpected antibody like anti-K or anti-c.

Incompatible red cells may "bleed out" but only if bleeding is brisk. Even then, a hemolytic reaction may occur later once the patient's antibody rebounds and destroys remaining antigen-positive donor red cells.

It's true that some patients have only cold-reactive antibodies that will not react at body temperature. But this does not explain why warm-reactive red cell antibodies cause few reactions

Why do so few patients transfused with un-crossmatched red cells in an emergency experience a hemolytic transfusion reaction? Select the one best reason.