If an unknown blood is added to anitiserum it will be of

Options

A. A' group if there is no clumping of RBC
B. A' or 'AB' if there is clumping of RBC
C. O group if there is poor clumping of RBC
D. none of the above

Explanation

To determine the blood group of an unknown sample when added to antiserum, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Blood Groups and Antisera**:
- Blood groups are determined by the presence of specific antigens on the surface of red blood cells (RBCs).
- Group A has A antigens and anti-B antibodies, Group B has B antigens and anti-A antibodies, Group AB has both A and B antigens, and Group O has neither A nor B antigens but has both anti-A and anti-B antibodies.

2. **Identify the Role of Antiserum**:
- Antiserum contains antibodies that react with specific antigens. For example, antiserum A contains anti-A antibodies, and antiserum B contains anti-B antibodies.

3. **Perform the Reaction**:
- When an unknown blood sample is mixed with antiserum, observe whether there is clumping (agglutination) of the RBCs.
- If the blood sample contains A antigens, it will clump when mixed with antiserum A due to the reaction between anti-A antibodies and A antigens.
- If the blood sample contains B antigens, it will clump with antiserum B.
- If the blood sample is AB, it will clump with both antisera.
- If the blood sample is O, there will be no clumping with either antiserum.

4. **Analyze the Results**:
- If there is **no clumping** with antiserum A, the blood is not A.
- If there is **no clumping** with antiserum B, the blood is not B.
- If there is **clumping** with both antisera, the blood is AB.
- If there is **no clumping** with either antiserum, the blood is O.

5. **Conclusion**:
- Based on the observations of clumping or lack thereof, you can determine the blood group of the unknown sample.