Assertion (A) : Crystalline solids are anisotropic in nature.
Reason (R) : Crystalline solids melt at a sharp and characteristic temperature.

Options

A. Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A).
B. Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A).
C. Assertion (A) is correct, but Reason (R) is incorrect statement.
D. Assertion (A) is incorrect, but Reason (R) is correct statement.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
**Assertion (A): Crystalline solids are anisotropic in nature.**

- **Definition of Anisotropic:** Anisotropic materials have different physical properties in different directions. This means that if you measure a property (like electrical resistance or refractive index) along different axes of the crystalline solid, you will get different values.

- **Reason for Anisotropy in Crystalline Solids:** This anisotropic behavior arises due to the ordered arrangement of particles in a crystalline solid. The regular and repeating arrangement of atoms or molecules leads to directional dependence of properties.

### Step 2: Understand the Reason
**Reason (R): Crystalline solids melt at a sharp and characteristic temperature.**

- **Melting Point of Crystalline Solids:** Pure crystalline solids do indeed have a sharp melting point. This means that they transition from solid to liquid at a specific temperature, which is characteristic of the substance. For example, pure ice melts at exactly 0°C under standard atmospheric pressure.

### Step 3: Analyze the Relationship Between Assertion and Reason
- **Both statements are true:** Both the assertion and the reason are true. Crystalline solids are indeed anisotropic, and they do melt at a sharp and characteristic temperature.

- **Is the reason a correct explanation for the assertion?** While both statements are true, the reason provided (that they melt at a sharp temperature) does not explain why they are anisotropic. Anisotropy is due to the arrangement of particles, not the melting behavior.

### Conclusion
- **Final Answer:** Both the assertion and the reason are true, but the reason is not the correct explanation for the assertion. Therefore, the correct option is that both statements are true, but the reason does not explain the assertion.

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