Assertion :- Mostly mammals are viviparous.
Reason :- Mammals having milk producing glands.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

To solve the question, we need to analyze the assertion and the reason provided, and determine their truthfulness and relationship.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states, "Mostly mammals are viviparous."
- Viviparous means that the organism gives birth to live young rather than laying eggs.
- Most mammals do indeed give birth to live young, making this assertion true.

2. **Understanding the Reason**:
- The reason states, "Mammals have milk-producing glands."
- This refers to mammary glands, which are characteristic of mammals and are responsible for producing milk to nourish their young.
- This statement is also true.

3. **Analyzing the Relationship**:
- While both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion.
- The fact that mammals are viviparous does not directly relate to the presence of milk-producing glands. Viviparity is about the mode of reproduction, while milk production is about nurturing the young.
- Therefore, the reason does not provide a correct explanation for the assertion.

4. **Conclusion**:
- Since both statements are true but the reason does not explain the assertion, the correct option is: "Both assertion and reason are true, but reason is not the correct explanation of assertion."

### Final Answer:
The correct option is: **Both assertion and reason are true, but reason is not the correct explanation of assertion.**

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