ABO blood grouping is based on `:-`

Options

A. Surface antibodies on RBC
B. Surface antigen on RBC
C. Surface antigen on WBC
D. Plasma antigens

Answer

**Step-by-Step Solution:**

1. **Understanding ABO Blood Grouping**: The ABO blood grouping system classifies human blood into four main types: A, B, AB, and O. This classification is based on the presence or absence of specific antigens on the surface of red blood cells (RBCs).

2. **Identifying Antigens**:
- Blood group A has A antigens on the surface of its RBCs and antibodies against B antigens in the plasma.
- Blood group B has B antigens on the surface of its RBCs and antibodies against A antigens in the plasma.
- Blood group AB has both A and B antigens on the surface of its RBCs and no antibodies against A or B in the plasma.
- Blood group O has no antigens on the surface of its RBCs but has both anti-A and anti-B antibodies in the plasma.

3. **Analyzing the Question**: The question asks what the ABO blood grouping is based on. The key aspect to focus on is the presence or absence of antigens on the RBCs.

4. **Evaluating Options**:
- The first option mentions "surface antibodies on the RBC," which is incorrect because blood grouping is determined by antigens, not antibodies.
- The second option states "surface antigen on the RBC," which correctly identifies that the blood grouping is based on the presence of A and B antigens on the RBC surface.

5. **Conclusion**: The correct answer is that ABO blood grouping is based on the presence of surface antigens on the RBC.

**Final Answer**: The ABO blood grouping is based on the surface antigens on the RBC.

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