$C{H_2} = C{H_2}\, \xrightarrow{{HOCl}} \,A\xrightarrow{{_R}}\begin{array}{*{20}{c}}
{C{H_2}OH} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_2}OH}
\end{array}$
$A\,\xrightarrow{{H{g^{2 + }}\,/\,{H^ + }}}B\,\xrightarrow{{NaB{H_4}}}C\,\xrightarrow[{conc.\,\,HCl}]{{ZnC{l_2}}}$ Turbidity within $5$ minutes.
$‘A’$ શું હશે?