Hemolysis Was Observed at Room Temperature When Testing a Patient's

Multiple Choice

Hemolysis was observed at room temperature when testing a patient's serum with reagent red cells used for screening.When this test was repeated using the patient's plasma,no hemolysis was observed.What was the most likely explanation for the different reactions?

A) The plasma sample was collected incorrectly.
B) The serum sample was contaminated.
C) Complement activation was inhibited by calcium in the plasma sample.
D) The serum sample was fresher.