Erthroblastosis foetalis can never occur in any child born parents having blood groups
I. Mother : Rh-ve, Father: Rh+ve
II. Mother : Rh-ve, Father: Rh-ve
III. Mother : Rh+ve, Father: Rh-ve
IV . Mother : Rh+ve, Father: Rh+ve

Options

A. I and II
B. III and IV
C. I, II and III
D. II, III and IV

Answer

To solve the question regarding erythroblastosis fetalis and the blood groups of parents, we need to analyze each option based on the Rh factor presence in the parents.

### Step-by-Step Solution:

1. **Understanding Erythroblastosis Fetalis**:
- Erythroblastosis fetalis occurs when an Rh-negative mother carries an Rh-positive fetus. If the fetal blood enters the mother's circulation, her body may produce antibodies against the Rh antigens, which can harm the fetus in subsequent pregnancies.

2. **Analyzing Each Option**:
- **Option I: Mother: Rh-negative, Father: Rh-positive**:
- In this case, the child can be Rh-positive. If the fetal blood enters the mother's circulation during delivery, she may produce antibodies against the Rh factor, leading to erythroblastosis fetalis.
- **Conclusion**: Erythroblastosis fetalis can occur.

- **Option II: Mother: Rh-negative, Father: Rh-negative**:
- Both parents are Rh-negative, meaning the child can only be Rh-negative. There is no Rh antigen for the mother to react against.
- **Conclusion**: Erythroblastosis fetalis can never occur.

- **Option III: Mother: Rh-positive, Father: Rh-negative**:
- The mother is Rh-positive, so she has Rh antigens. The child can be Rh-positive or Rh-negative, but the mother will not produce antibodies against Rh antigens since she already has them.
- **Conclusion**: Erythroblastosis fetalis can never occur.

- **Option IV: Mother: Rh-positive, Father: Rh-positive**:
- Both parents are Rh-positive, so the child will also be Rh-positive. The mother will not produce antibodies against Rh antigens.
- **Conclusion**: Erythroblastosis fetalis can never occur.

3. **Final Answer**:
- Erythroblastosis fetalis can never occur in the following scenarios:
- II. Mother: Rh-negative, Father: Rh-negative
- III. Mother: Rh-positive, Father: Rh-negative
- IV. Mother: Rh-positive, Father: Rh-positive

Thus, the answer is **II, III, and IV**.