The ease of dehydrohalogenation of alkyl halide with alcoholic $KOH$ is:

Given below are two statements:
Statement $I$: $(CH_3)_3C-CH_2-Cl$ will undergo $S_N1$ reaction even though it is a primary halide.
Statement $II$: It will not undergo $S_N2$ reaction very easily even though it is a primary halide.
In the light of the above statements,choose the most appropriate answer from the options given below:

The order of $S_{N^1}$ reactivity in aqueous acetic acid solution for the compounds:
$(1)$ $CH_3-CO-CH_2-Cl$
$(2)$ $CH_3-CH_2-CH_2-Cl$
$(3)$ $(CH_3)_3C-Cl$

The major product of the following reaction is:

Explain the mechanism of the bimolecular nucleophilic substitution $(S_N2)$ reaction with the example of $CH_3Cl$.

The $S_N2$ product of the following reaction is: