The product $(B)$ is

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A):$ $R-I$ undergoes $S_N2$ reaction faster than $R-Cl$.
Reason $(R):$ Iodine is a better leaving group because of its large size.
In the light of the above statements,choose the correct answer from the options given below:

On treatment with chlorine in the presence of sunlight,toluene gives the product

The rate of $S_{N}2$ reaction is maximum when the solvent is

Which of the following is most reactive for $S_{N}1$ reaction?

The reaction $(CH_3)_3C - Br + H_2O \rightarrow (CH_3)_3C - OH + HBr$ is an example of which type of reaction?