The correct order of acid catalysed dehydration of alcohols is:

Options

A. `1^@ gt 2^@ gt 3^@`
B. `3^@ gt 2^@ gt 1^@`
C. `2^@ gt 1^@ gt 3^@`
D. `1^@ gt 3^@ gt 2^@`

Explanation

To determine the correct order of acid-catalyzed dehydration of alcohols, we need to analyze the stability of carbocations formed during the reaction. The stability of carbocations is crucial because the more stable the carbocation, the more likely it is to form, and thus, the more likely dehydration will occur.

### Step-by-Step Solution:

1. **Understand Acid-Catalyzed Dehydration**:
- Acid-catalyzed dehydration involves the removal of water (H2O) from an alcohol in the presence of an acid. This process typically leads to the formation of an alkene.

2. **Formation of Carbocation**:
- When an alcohol is protonated by the acid, it forms a protonated alcohol (alkyl oxonium ion). This intermediate can lose a water molecule to form a carbocation.

3. **Stability of Carbocations**:
- The stability of carbocations follows this order:
- Tertiary (3°) > Secondary (2°) > Primary (1°)
- Tertiary carbocations are the most stable due to the presence of three alkyl groups that can donate electron density and stabilize the positive charge. Secondary carbocations are less stable, and primary carbocations are the least stable.

4. **Dehydration Order**:
- Since the rate of dehydration is directly related to the stability of the carbocation formed, the order of dehydration will follow the stability of the carbocations:
- Tertiary alcohols will dehydrate the fastest, followed by secondary alcohols, and finally primary alcohols.

5. **Conclusion**:
- Therefore, the correct order of acid-catalyzed dehydration of alcohols is:
- **Tertiary > Secondary > Primary** (3° > 2° > 1°).

### Final Answer:
The correct order of acid-catalyzed dehydration of alcohols is: **Tertiary > Secondary > Primary**.