1
2
3 $\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
Ph-C-\,C{{H}_{2}}-C{{O}_{2}}H \\
\end{matrix}$
4 $\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
C{{H}_{3}}-C-\,C{{H}_{2}}-C{{O}_{2}}H \\
\end{matrix}$
Explanation:
\((b)\) It violates bredt's rule.