The reaction condition leading to the best yields of ${\mathrm{C}}_2{\mathrm{H}}_5\mathrm{Cl}$ is

$\mathrm{Ph}-\mathrm{C}\equiv \mathrm{C}-{\mathrm{CH}}_3 \stackrel{{\mathrm{Hg}}^{2+}/{\mathrm{H}}^{+}}{\to } \mathrm{A}$

What would be the final product $\mathrm{A}$?

The main product of the following reaction is: ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_2\left(\mathrm{OH}\right)\mathrm{CHCH}{\left({\mathrm{CH}}_3\right)}_2\stackrel{\mathrm{Concentrate} {\mathrm{H}}_2{\mathrm{SO}}_4}{⟶}$