Assertion : Identical twins are produced during two births , resulting from the division of a single fertilized egg .
Reaosn : They are of the different sex and otherwise genetically identical.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Identical twins are produced during two births, resulting from the division of a single fertilized egg." This statement is misleading because identical twins (also known as monozygotic twins) are not produced during two separate births; they are typically born at the same time as a result of the splitting of a single fertilized egg.

**Hint**: Think about how identical twins are formed and whether they can be born in separate instances.

2. **Understanding the Reason**: The reason provided states that "They are of different sex and otherwise genetically identical." This is incorrect because identical twins are genetically identical and always of the same sex. They arise from the same zygote and share the same genetic material.

**Hint**: Recall the characteristics of identical twins and whether they can be of different sexes.

3. **Evaluating the Truth of the Statements**:
- The assertion is false because identical twins do not result from two births.
- The reason is also false because identical twins cannot be of different sexes; they are always the same sex.

**Hint**: Assess each part of the assertion and reason independently to determine their truthfulness.

4. **Conclusion**: Since both the assertion and the reason are false, the correct answer is that both the assertion and reason are false.

**Hint**: Look for the option that states both statements are false to find the correct answer.

### Final Answer:
Both the assertion and reason are false.