Which of the folliwning ether wil always give `SN^(2)` mechanism in acidic as well as basic conditions?

Options

A.
B.
C.
D. All

Explanation

To determine which ether will always give an SN2 mechanism in both acidic and basic conditions, we need to analyze the structure of the ethers provided in the options. The key points to consider are the nature of the alkyl groups attached to the ether and how they influence the reaction mechanism.

### Step-by-Step Solution:

1. **Understand the Mechanisms**:
- **SN1 Mechanism**: This involves the formation of a carbocation intermediate. The stability of the carbocation is crucial; tertiary carbocations are more stable than secondary, which are more stable than primary. This mechanism is favored in polar protic solvents and with substrates that can stabilize the carbocation.
- **SN2 Mechanism**: This is a one-step process where the nucleophile attacks the electrophile simultaneously as the leaving group departs. The reaction rate depends on steric hindrance; less hindered (primary) substrates favor SN2.

2. **Identify the Ethers**:
- We need to analyze the ethers given in the options. For an ether to undergo SN2, it should ideally have primary alkyl groups attached to the oxygen atom.

3. **Evaluate Each Ether**:
- **Option A**: If it has two primary alkyl groups, it will favor SN2 due to low steric hindrance.
- **Option B**: Similar to option A, if it has primary alkyl groups, it will also favor SN2.
- **Option C**: Again, if it contains primary alkyl groups, it will favor SN2.
- **Option D**: If this ether has primary alkyl groups, it will also favor SN2.

4. **Conclusion**:
- Since all options have primary alkyl groups, they will all favor the SN2 mechanism due to low steric hindrance. Therefore, the answer is that all ethers listed will give an SN2 mechanism in both acidic and basic conditions.

### Final Answer:
All ethers with primary alkyl groups will always give an SN2 mechanism in both acidic and basic conditions.