Statement I: High concentration of strong nucleophilic reagent with secondary alkyl halides which do not have bulky substituents will follow \(S_N2\) mechanism.
Statement II: A secondary alkyl halide when treated with a large excess of ethanol follows \(S_N1\) mechanism.
In the light of the above statements, choose the most appropriate from the questions given below:
An organic compound $[ A ]\left( C _4 H _{11} N \right)$, shows optical activity and gives $N _2$ gas on treatment with The structure of $A$ is :