Assertion :- Sperm entry causes a rearrangement of materials in the ooplasm .
Reason:-Path of the male pronucleus toward the female pronucleus is maked in the ovum as a copulation path .

Options

A. If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion .
B. If both Assertion and Reason are true but Reason is not correct explanation of the Assertion .
C. If Assertion is true but the Reason is false .
D. If Both Assertion and Reason Are false

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that "Sperm entry causes a rearrangement of materials in the ooplasm." This is true because when a sperm enters the ovum (egg), it triggers various changes in the cytoplasm (ooplasm) of the egg. This includes the redistribution of organelles and cytoplasmic components, which is essential for the fertilization process.

2. **Understanding the Reason**: The reason provided is that "The path of the male pronucleus toward the female pronucleus is marked in the ovum as a copulation path." This statement is also true. The sperm travels through the female reproductive tract to reach the ovum, and this path can be referred to as the copulation path.

3. **Evaluating the Relationship**: While both the assertion and reason are true, the reason does not directly explain the assertion. The assertion focuses on the rearrangement of materials in the ooplasm due to sperm entry, while the reason discusses the path taken by the male pronucleus. Therefore, the reason does not serve as a justification for the assertion.

4. **Conclusion**: Since both statements are true but the reason does not explain the assertion, the correct answer is that both are true, but the reason is not the correct explanation of the assertion. Thus, the answer is option B.