different sizes of red blood cells different sizes of white blood cells different marker proteins on red blood cells different marker proteins on white blood cells
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: How do blood types differ from one another in the ABO blood classification?
Possibilities:
- different sizes of red blood cells
- different sizes of white blood cells
- different marker proteins on red blood cells
- different marker proteins on white blood cells

different marker proteins on red blood cells