Which of the following nucleophilie has highest `S_(N)^(2)` reactivity?

Options

A. MeO^(-)
B. `Me-CH_(2)-O^(-)`
C. `Me_(2)-CHO^(-)`
D. `Me_(3)CO^(-)`

Explanation

To determine which of the following nucleophiles has the highest \( S_N^2 \) reactivity, we need to analyze the structure and steric hindrance of the given nucleophiles, which are all alkoxides.

### Step-by-Step Solution:

1. **Understand the \( S_N^2 \) Mechanism**:
- The \( S_N^2 \) (Substitution Nucleophilic Bimolecular) reaction is a one-step mechanism where the nucleophile attacks the electrophile from the opposite side of the leaving group. This results in the inversion of configuration at the carbon center.

2. **Identify the Nucleophiles**:
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