A baby of blood group A cannot belong to parents of blood group
(a) Husband O, wife AB
(b) Husband A, wife B
(c) Husband B, wife O
(d) Husband AB, wife A

Options

A. Husband O, wife AB
B. Husband A, wife B
C. Husband B, wife O
D. Husband AB, wife A

Answer

To determine which set of parents cannot produce a baby with blood group A, we need to analyze the possible blood groups of the offspring based on the blood groups of the parents.

### Step-by-Step Solution:

1. **Understanding Blood Groups and Genotypes**:
- Blood group A can have genotypes IAIA or IAIO.
- Blood group B can have genotypes IBIB or IBIO.
- Blood group AB has the genotype IAIB.
- Blood group O has the genotype I O I O.

2. **Analyzing Each Option**:
- **Option (a): Husband O, Wife AB**:
- Husband's genotype: I O I O (O)
- Wife's genotype: I A I B (AB)
- Possible offspring genotypes:
- From O (I O) and AB (I A, I B): Possible blood groups are A (IAIO) and B (IBIO).
- Conclusion: Child can have blood group A. **(Not the correct answer)**

- **Option (b): Husband A, Wife B**:
- Husband's genotype: I A I O or I A I A (A)
- Wife's genotype: I B I O or I B I B (B)
- Possible offspring genotypes:
- Possible blood groups are A (IAIO), B (IBIO), and AB (IAIB).
- Conclusion: Child can have blood group A. **(Not the correct answer)**

- **Option (c): Husband B, Wife O**:
- Husband's genotype: I B I O or I B I B (B)
- Wife's genotype: I O I O (O)
- Possible offspring genotypes:
- Possible blood groups are B (IBIO) and O (I O I O).
- Conclusion: Child cannot have blood group A. **(This is the correct answer)**

- **Option (d): Husband AB, Wife A**:
- Husband's genotype: I A I B (AB)
- Wife's genotype: I A I O or I A I A (A)
- Possible offspring genotypes:
- Possible blood groups are A (IAIO), B (IBIO), and AB (IAIB).
- Conclusion: Child can have blood group A. **(Not the correct answer)**

3. **Final Conclusion**:
- The baby of blood group A cannot belong to parents with blood group **Husband B, Wife O** (Option C).