Which of the blood groups can be given to any person:

Options

A. A
B. Back cross
C. AB
D. O

Answer

To determine which blood group can be given to any person, we need to analyze the blood groups and their compatibility based on the presence of antigens and antibodies.

### Step-by-Step Solution:

1. **Understand Blood Group Basics**:
- Blood groups are determined by the presence of specific antigens on the surface of red blood cells (RBCs).
- The main blood groups are A, B, AB, and O, which are controlled by three alleles: IA, IB, and iO.

2. **Identify Antigens and Antibodies**:
- **Blood Group A**: Has A antigens on RBCs and B antibodies in plasma.
- **Blood Group B**: Has B antigens on RBCs and A antibodies in plasma.
- **Blood Group AB**: Has both A and B antigens on RBCs and no antibodies in plasma.
- **Blood Group O**: Has no antigens on RBCs and both A and B antibodies in plasma.

3. **Determine Compatibility**:
- When blood is transfused, the recipient's antibodies can react against the donor's antigens.
- For example, if a person with blood group A receives blood group B, the B antigens will trigger an immune response due to the presence of A antibodies, leading to agglutination and potentially severe reactions.

4. **Identify the Universal Donor**:
- The blood group O has no antigens on its RBCs, meaning it does not provoke an immune response in recipients regardless of their blood type.
- Therefore, individuals with blood group O can donate blood to anyone without the risk of agglutination.

5. **Conclusion**:
- The blood group that can be given to any person is **O**. Thus, the answer is option D.