How does the Hh blood group system, also known as the Bombay phenotype, affect the expression of ABO blood groups?

A It suppresses the expression of A and B antigens ✓
B It enhances the expression of A and B antigens
C It has no effect on ABO blood group expression
D It changes the expression of ABO blood groups to a different antigen

Explanation

The Hh blood group system, or Bombay phenotype, is characterized by the absence or very weak expression of A and B antigens on red blood cells due to a deficiency in the enzyme fucosyltransferase, which is necessary for the synthesis of these antigens.

Source

Immunohematology textbooks
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Medium MEDICAL Confidence: high