Methyl group `(CH_3 )` shows the following effect:

Options

A. Electromeric effect
B. `-ve` inductive effect
C. `+ve` inductive effect
D. Mesomeric effect

Explanation

To determine the effect exhibited by the methyl group (CH₃), we need to analyze the options provided and understand the nature of the methyl group in organic chemistry.

### Step-by-Step Solution:

1. **Understanding the Methyl Group**:
- The methyl group (CH₃) is a simple alkyl group. It consists of one carbon atom bonded to three hydrogen atoms.

2. **Identifying the Effects**:
- **Electromeric Effect**: This effect is temporary and occurs in the presence of an electrophile or nucleophile, where the electrons shift towards the positive or negative charge. The methyl group does not exhibit this effect.
- **Inductive Effect**: This is a permanent effect due to the electronegativity difference between atoms. It can be positive or negative.
- **Negative Inductive Effect (-I)**: This occurs when a group withdraws electron density from the rest of the molecule.
- **Positive Inductive Effect (+I)**: This occurs when a group donates electron density towards the rest of the molecule.

3. **Analyzing the Methyl Group**:
- The methyl group is considered an electron-donating group because it can push electron density towards the attached carbon chain. Therefore, it exhibits a positive inductive effect (+I).

4. **Mesomeric Effect**:
- This effect involves the delocalization of electrons through π bonds or lone pairs. The methyl group does not participate in resonance due to the absence of π bonds, so it does not exhibit a mesomeric effect.

5. **Conclusion**:
- Based on the analysis, the methyl group shows a positive inductive effect (+I). Therefore, the correct answer is **C**.

### Final Answer:
The methyl group (CH₃) shows a **positive inductive effect (+I)**.