Assertion : Crystalline solids have short range order.
Reason : Amorphous solids have long range order.

Options

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

Explanation

To analyze the assertion and reason provided in the question, we need to understand the characteristics of crystalline and amorphous solids.

### Step-by-step Solution:

1. **Understanding Crystalline Solids**:
- Crystalline solids are defined by their orderly and repeating arrangement of atoms, ions, or molecules. This structure extends throughout the solid, which is known as long-range order.
- **Conclusion**: The assertion that "Crystalline solids have short range order" is **false**. They actually exhibit long-range order.

2. **Understanding Amorphous Solids**:
- Amorphous solids, on the other hand, lack a well-defined long-range order. Their atomic arrangement is more random and does not repeat in a regular pattern.
- **Conclusion**: The reason that "Amorphous solids have long range order" is also **false**. They have short-range order but no long-range order.

3. **Final Evaluation**:
- Since both the assertion and the reason are false, we conclude that the statement is incorrect. Crystalline solids exhibit long-range order, while amorphous solids do not have long-range order.

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