What is the name of the phenomenon where an individual's red blood cells have a mixed population of cells with different ABO blood group antigens?

A Chimerism ✓
B Mosaicism
C Genetic drift
D Somatic mutation

Explanation

Chimerism refers to the presence of two or more different cell populations in an individual, often resulting from bone marrow transplantation or twin-to-twin transfusion.

Source

Transfusion Medicine textbook
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Hard MEDICAL Confidence: high