Which blood group can safely be transfused in emergency when there is no time to analyse the blood group of recipient ?

Options

A. (a) O and `Rh^(-)`
B. (b) O and `Rh^(+)`
C. (c) B and `Rh^(-)`
D. (d) AB and `Rh^(+)`

Answer

To determine which blood group can be safely transfused in an emergency when there is no time to analyze the recipient's blood type, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Blood Groups**: Blood groups are classified based on the presence or absence of specific antigens on the surface of red blood cells. The main blood group systems are A, B, AB, and O, along with the Rh factor (positive or negative).

2. **Identify Antigens**:
- Blood group A has A antigens.
- Blood group B has B antigens.
- Blood group AB has both A and B antigens.
- Blood group O has no A or B antigens.
- Rh positive has the Rh antigen, while Rh negative does not.

3. **Consider Compatibility**:
- Transfusing blood with incompatible antigens can lead to severe immune reactions.
- For example, if a person with blood group A receives blood group B, their immune system will attack the foreign B antigens.

4. **Evaluate Options**:
- **Option A (O and Rh negative)**: Blood group O has no A or B antigens, making it universally acceptable. Rh negative means it does not have the Rh antigen, which is also safe for Rh positive recipients.
- **Option B (O and Rh positive)**: Blood group O is safe, but Rh positive can cause reactions in Rh negative recipients.
- **Option C (B and Rh negative)**: Blood group B has B antigens, which can cause reactions in A or AB recipients.
- **Option D (A, B and Rh positive)**: Blood groups A and B have specific antigens that can cause reactions in recipients with different blood types.

5. **Conclusion**: Given that blood group O has no antigens that would trigger an immune response and can be safely transfused to anyone, the best choice is **Option A: O and Rh negative**. This blood type can be transfused in emergencies without the risk of severe allergic reactions.

### Final Answer:
**The blood group that can safely be transfused in an emergency when there is no time to analyze the blood group of the recipient is O and Rh negative.**

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