Total number of species from the following with central atom utilising $2 \mathrm{p}^2$ hybrid orbitals for bonding is.. . . . . . . .$\mathrm{NH}_3, \mathrm{SO}_2, \mathrm{SiO}_2, \mathrm{BeCl}_2, \mathrm{C}_2 \mathrm{H}_2, \mathrm{C}_2 \mathrm{H}_4, \mathrm{BCl}_3, \mathrm{HCHO}$, $\mathrm{C}_6 \mathrm{H}_6, \mathrm{BF}_3, \mathrm{C}_2 \mathrm{H}_4 \mathrm{Cl}_2$
→$\begin{matrix}
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O \\
\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|| \\
Ph-CH-C-H \\
|\,\,\,\,\,\,\,\,\,\, \\
OH\,\,\,\,\,\,\, \\
\end{matrix}\,\xrightarrow[{{H}_{2}}O]{H{{O}^{\Theta }}}\,(B)$ ; $(A)$ and $(B)$ are isomer and isomerization effectively carried out by trace of base $(B)$ . Identify $(B)$
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