Which among the following halide/s will not show $$\mathrm{S_N 1}$$ reaction:

(A) $$\mathrm{H}_2 \mathrm{C}=\mathrm{CH}-\mathrm{CH}_2 \mathrm{Cl}$$

(B) $$\mathrm{CH}_3-\mathrm{CH}=\mathrm{CH}-\mathrm{Cl}$$

(C)

(D)

Choose the most appropriate answer from the options given below :

The correct statement regarding nucleophilic substitution reaction in a chiral alkyl halide is ;

In the following reaction 'X' is