The major elimination product in the above reaction is

The major product of the following reaction is :

In the following reaction sequence, structures of $\mathrm{A}$ and $\mathrm{B}$ are, respectively

The major product in the following reaction is :

KI in acetone, undergoes S_N2 reaction with each of P, Q, R and S. The rates of the reaction vary as

The major products of the following reaction are :

Here, $\mathrm{Z}$ is:

For each of the following reactions, indicate whether elimination will occur via an $\mathrm{E}2$ or an $\mathrm{E}1$ reaction. Give the major product in each case.

For each of the following reactions, indicate whether
elimination will occur via an $\mathrm{E}2$ or an $\mathrm{E}1$ reaction. Give
the major product in each case.