Which of the following will be least reactive towards nucleophilic substitution reaction ?

Options

A.
B.
C.
D.

Explanation

To determine which compound is least reactive towards nucleophilic substitution reactions, we need to analyze the given options based on the presence of functional groups, the type of bonds, and the potential for resonance or conjugation.

### Step-by-Step Solution:

1. **Identify the Compounds**:
We need to look at the compounds provided in the options. Let's denote them as A, B, C, and D for clarity.

2. **Understand Nucleophilic Substitution**:
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