Blood of AB group cannot be given to B group patient because

Options

A. patient has antibodies b
B. patient lacks antibodies b
C. patient lacks anti-a and anti b antibodies
D. patient has antibodies a

Explanation

### Step-by-Step Solution:

1. **Understanding Blood Groups**: Blood groups are classified based on the presence of specific antigens on the surface of red blood cells (RBCs) and antibodies in the plasma. The main blood groups in the ABO system are A, B, AB, and O.

2. **Identifying Antigens and Antibodies**:
- **Blood Group B**: This group has B antigens on the surface of its RBCs and contains anti-A antibodies in the plasma.
- **Blood Group AB**: This group has both A and B antigens on the surface of its RBCs and does not contain any antibodies (neither anti-A nor anti-B) in the plasma.

3. **Compatibility of Blood Transfusion**: When considering blood transfusions, it is crucial to match the donor's blood group with the recipient's blood group to prevent adverse reactions. The presence of antibodies in the recipient's plasma can attack the antigens present in the donor's blood.

4. **Analyzing the Situation**: If a patient with blood group B receives blood from a donor with blood group AB:
- The B group patient has anti-A antibodies in their plasma.
- The AB group blood contains A antigens (which would trigger a reaction with the anti-A antibodies present in the B group patient).

5. **Conclusion**: Therefore, blood from an AB group cannot be given to a B group patient because the anti-A antibodies in the B group patient would react against the A antigens present in the AB blood, leading to a potentially dangerous transfusion reaction.

### Final Answer:
Blood of AB group cannot be given to B group patient because the B group patient has anti-A antibodies that will react against the A antigens present in the AB blood.

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