The compound which will have the lowest rate towards nucleophilc aromatic substitution on treatment with `OH^(–)` is :

Options

A.
B.
C.
D.

Answer

To determine which compound will have the lowest rate towards nucleophilic aromatic substitution when treated with OH⁻, we need to analyze the effects of substituents on the aromatic ring.

### Step-by-Step Solution:

1. **Understanding Nucleophilic Aromatic Substitution**:
- Nucleophilic aromatic substitution occurs when a nucleophile attacks an aromatic compound, typically at a carbon atom bonded to a leaving group (like Cl). The presence of electron-withdrawing groups (EWGs) can enhance this reaction, while electron-donating groups (EDGs) can hinder it.

2. **Identifying the Compounds**:
- We have several options with different substituents on the aromatic ring. The key substituents to consider are:
- Electron-withdrawing groups (e.g., NO₂, CN) which stabilize the negative charge during the reaction.
- Electron-donating groups (e.g., -OCH₃, -CH₃) which destabilize the negative charge.

3. **Analyzing the Position of Substituents**:
- The position of the substituents relative to the leaving group is crucial:
- **Ortho and Para Positions**: If an EWG is present at the ortho or para position, it can stabilize the intermediate formed during nucleophilic attack, facilitating the reaction.
- **Meta Position**: If an EWG is at the meta position, it does not stabilize the intermediate effectively, making the reaction slower.

4. **Evaluating the Options**:
- If one of the options has a strong EWG like NO₂ at the meta position, it will significantly lower the rate of nucleophilic substitution because it does not stabilize the intermediate formed during the attack.
- Compare the options to identify which one has a strong EWG at the meta position.

5. **Conclusion**:
- The compound with the NO₂ group at the meta position will have the lowest rate of nucleophilic aromatic substitution when treated with OH⁻. This is because the electron-withdrawing effect of the NO₂ group at the meta position does not aid in stabilizing the negative charge that forms during the reaction.

### Final Answer:
The compound which will have the lowest rate towards nucleophilic aromatic substitution on treatment with OH⁻ is the one with the NO₂ group at the meta position (Option 2).