What is the significance of the 'Ch/Rg' notation in the context of Rh blood group system?

A It denotes the presence of a specific antigen
B It denotes the absence of a specific antigen
C It denotes a variant of the RhD antigen
D It denotes a combination of Rh antigens ✓

Explanation

The 'Ch/Rg' notation refers to a combination of Rh antigens, specifically the presence of both C and h (or Rg) antigens on the same red blood cell.

Source

ISBT Guidelines for Blood Grouping and Crossmatching
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Hard MEDICAL Confidence: medium