What is the purpose of using a 'washing' step in the preparation of red blood cells for transfusion?

A To remove plasma proteins and reduce the risk of allergic reactions ✓
B To remove white blood cells and reduce the risk of graft-versus-host disease
C To remove platelets and reduce the risk of thrombosis
D To remove antibiotics and reduce the risk of antibiotic resistance

Explanation

The washing step is used to remove plasma proteins, which can cause allergic reactions in some recipients, and reduce the risk of an adverse reaction to the transfused blood.

Source

AABB Technical Manual
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Easy MEDICAL Confidence: high