Correct option is C
Explanation-
Mother's Blood Group: O
Genotype: O = ii (only one possibility)
Can only pass "i" allele to the baby
Father's Blood Group: AB
Genotype: AB = IAIB
Can pass either IA or IB allele to the baby
So the baby’s possible blood groups:
From mother: i
From father: IA or IB
Baby can be:
IAi → Blood group A
IBi → Blood group B
Baby cannot be:
AB (IAIB) – child would need both IA and IB alleles, but mother only provides i
O (ii) – both parents must provide "i", but father doesn't have "i"
Step 2: Rh Factor Inheritance
Mother = Rh +ve, so genotype can be either (+ +) or (+ –).
Father = Rh –ve, so genotype must be (– –).
Now let’s consider both Rh cases:
Case 1: Mother is homozygous (+ +)
Cross: (+ +) × (– –)
→ All offspring: (+ –) → Rh +ve only
So, if the mother is homozygous,
Baby cannot be Rh –ve.
Case 2: Mother is heterozygous (+ –)
Cross: (+ –) × (– –)
→ 50% (+ –) (Rh +ve) and 50% (– –) (Rh –ve)
So, baby could be Rh –ve, but only if the mother carries the Rh – gene (which is not guaranteed).
-When mother is Rh +ve, she is usually considered homozygous (+ +) unless otherwise mentioned.
-That means she can only pass Rh + to the child.
-Hence, the baby will inherit Rh + from mother and Rh – from father → resulting in Rh +ve.
-Therefore, the most definite and correct possible baby type is:
A and Rh +ve (Option 3)
