The following blood group is called universal recipient

Options

A. A
B. B
C. AB
D. O

Answer

### Step-by-Step Solution:

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

2. **Identifying the Universal Recipient**: The term "universal recipient" refers to a blood group that can receive blood from any other blood group without causing an immune reaction.

3. **Analyzing Blood Group AB**: Blood group AB has both A and B antigens present on its RBCs. This means that when blood from any other group (A, B, or O) is introduced, the AB recipient's immune system does not recognize these antigens as foreign.

4. **Absence of Antibodies in AB**: Individuals with blood group AB do not produce antibodies against A or B antigens. Therefore, they can accept blood from any donor without the risk of an allergic or immune response.

5. **Conclusion**: Since blood group AB can receive blood from all other blood groups without causing any adverse reactions, it is classified as the universal recipient.

6. **Eliminating Other Options**:
- **Blood Group A**: Has A antigens and produces antibodies against B antigens, making it unsuitable for receiving blood from group B or AB.
- **Blood Group B**: Has B antigens and produces antibodies against A antigens, making it unsuitable for receiving blood from group A or AB.
- **Blood Group O**: Lacks both A and B antigens, making it the universal donor but not a universal recipient.

### Final Answer:
The blood group that is called the universal recipient is **blood group AB**.

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