What is contained in a bag referred to as "low titer O blood"?

The term "low titer O blood" refers specifically to a blood product that contains Type O red blood cells along with plasma that has a low concentration of antibodies against other blood types. This composition is particularly important in emergency settings, especially in trauma situations, where it may not be possible to determine a patient's blood type quickly.

Type O red blood cells are considered universal donors because they can be transfused to patients of any blood type without a significant risk of transfusion reactions. The low-titer plasma reduces the potential for hemolytic reactions in recipients who may have pre-existing antibodies against other blood types; this is crucial in emergency transfusions when rapid action is needed.

In contrast, the other options describe blood components that do not correlate with what is specifically meant by "low titer O blood." For instance, Type A and Type B red blood cells do not match the characteristic of low titer O blood, which is defined by the presence of Type O red cells. Plasma only would lack the red blood cells crucial for oxygen transport in an emergency scenario.