The possible genotype of blood group 'O' is:

Options

A. `I^(B)`i
B. `I^(A)`i
C. ii
D. `I^(A)I^(B)`

Answer

To determine the possible genotype for blood group 'O', we need to understand the genetics of blood groups, specifically the alleles involved.

### Step-by-Step Solution:

1. **Understanding Blood Group Genetics**:
Blood groups are determined by three alleles:
- \( I^A \) (A allele)
- \( I^B \) (B allele)
- \( i^O \) (O allele)

2. **Dominance of Alleles**:
- The alleles \( I^A \) and \( I^B \) are dominant over \( i^O \).
- This means that if either \( I^A \) or \( I^B \) is present with \( i^O \), the blood group will be A or B, respectively.

3. **Homozygous Condition for Blood Group O**:
- The blood group O occurs when the genotype is homozygous for the recessive allele \( i^O \).
- Therefore, the only genotype that results in blood group O is \( ii \) (homozygous recessive).

4. **Exclusion of Other Genotypes**:
- \( I^B i^O \) leads to blood group B.
- \( I^A i^O \) leads to blood group A.
- \( I^A I^B \) leads to blood group AB.
- Hence, none of these can result in blood group O.

5. **Conclusion**:
- The possible genotype for blood group O is \( ii \).

### Final Answer:
The possible genotype of blood group 'O' is \( ii \).

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