Universal donor blood group is

Options

A. `B^(-)`
B. `A^(+)`
C. `O^(+)`
D. `O^(-)`

Answer

To determine the universal donor blood group, we need to understand the compatibility of blood types in transfusions. Here’s a step-by-step solution:

1. **Understanding Blood Groups**: Human blood is classified into four main groups: A, B, AB, and O. Each group can be Rh-positive (+) or Rh-negative (-), leading to a total of eight blood types.

2. **Antigens and Antibodies**: Blood groups are determined by the presence or absence of specific antigens on the surface of red blood cells. For example:
- Type A has A antigens and anti-B antibodies.
- Type B has B antigens and anti-A antibodies.
- Type AB has both A and B antigens and no anti-A or anti-B antibodies.
- Type O has no A or B antigens but has both anti-A and anti-B antibodies.

3. **Universal Donor Definition**: A universal donor is a blood type that can be transfused to any recipient without causing an immune reaction. This means the donor's blood must not have antigens that could trigger an immune response in the recipient.

4. **Identifying the Universal Donor**:
- Type O blood does not have A or B antigens, making it compatible with all other blood types.
- Among the O blood types, O negative (O-) is considered the universal donor because it lacks Rh factor as well, which means it can be given to Rh-positive and Rh-negative recipients.

5. **Conclusion**: Therefore, the universal donor blood group is O negative (O-).

**Final Answer**: The universal donor blood group is O negative (Option D).

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