b
\(\begin{array}{*{20}{c}}
  {C{H_3} - C - H} \\ 
  {\,\,\,\,\,||} \\ 
  {\,\,\,\,\,O} 
\end{array}\) \(\xrightarrow{{HCN}}\) \(\begin{array}{*{20}{c}}
  {C{H_3} - CH - CN} \\ 
  {|\,\,\,\,\,} \\ 
  {OH} 
\end{array}\) \(\xrightarrow{{{H^ \oplus }\,/\,{H_2}O}}\) \(\underset{(Rac.\,\,mixture)}{\mathop{\begin{matrix}
   C{{H}_{3}}-\overset{*}{\mathop{C}}\,H-COOH  \\
   |\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   OH\,\,\,\,\,\,\,\,\,  \\
\end{matrix}}}\,\)