Identify the final product $[D]$ obtained in the following sequence of reactions.

Which compound has the highest reactivity towards $S_{N}2$ reaction?

In the above reaction,the maximum Saytzeff product will be obtained when $X$ is:

Given below are two statements:
Statement $(I)$: Benzyl chloride reacts faster in $S_N1$ mechanism than ethyl chloride.
Statement $(II)$: Ethyl carbocation intermediate is less stabilized by hyperconjugation than benzyl carbocation by resonance.
In the light of the above statements, choose the correct answer from the options given below:

When $AgNO_3$ comes in contact with skin,it leaves a black stain. This is because of

In the dehydrohalogenation of $2$-bromobutane,which conformation leads to the formation of $cis$-but-$2$-ene?