In which case will `SE` not be in `m-` position?

Options

A.
B.
C.
D.

Explanation

To determine in which case the electrophilic substitution (SE) will not occur at the meta position, we need to analyze the substituents attached to the benzene ring. The key is to identify whether the substituents are electron-donating or electron-withdrawing and their directing effects on electrophilic substitution reactions.

### Step-by-Step Solution:

1. **Identify the Substituents**: We need to look at the groups attached to the benzene ring in each case. The groups mentioned are COO, a quaternary amine, ethene, and CF3.

2. **Analyze Each Group**:
- **Group A (COO)**: This is a carboxylate group, which is an electron-withdrawing group. Electron-withdrawing groups direct electrophilic substitution to the meta position. Therefore, this group does not satisfy our condition as it directs to the meta position.

- **Group B (Quaternary Amine)**: This group is also an electron-withdrawing group. Like the carboxylate group, it will also direct electrophilic substitution to the meta position. Thus, this group cannot be our answer either.

- **Group C (Ethene)**: Ethene is a double bond that can act as a deactivating group but it is also ortho-para directing. This means that it will not direct the electrophile to the meta position. Therefore, this group is a candidate for our answer.

- **Group D (CF3)**: The trifluoromethyl group (CF3) is a strong electron-withdrawing group. It directs electrophilic substitution to the meta position, similar to the previous two groups. Hence, this group cannot be our answer.

3. **Conclusion**: The only substituent that does not direct electrophilic substitution to the meta position is the ethene group (Group C). Therefore, the answer to the question is **option C**.

### Final Answer:
The electrophilic substitution will not occur at the meta position in the case of **option C (Ethene)**.

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