d
If we observe the haloform reaction carefully, we see that \(-COCH_3\) group is first halogenated to the trihalo \(-COCX_3\) through monohalogeno and dihalogeno compound. It is the \(-COCX_3\) part which then undergoes nucleophilic addition. The product easily loses \(-CX_3\) since it is a very good leaving group

Thus all compounds \((I\, to \,IV)\) are ultimately converted to \(CHCl_3\) (chloroform)

\(\mathop {\begin{array}{*{20}{c}}
  \,\,\,\,{O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  \,\,\,\,{||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {C{H_3} - C - C{H_3}\xrightarrow{{{X_2},O{H^ - }}}} 
\end{array}}\limits_{I\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \) \(\mathop {\begin{array}{*{20}{c}}
  {\,\,\,\,\,\,\,\,\,\,\,O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {\,\,\,\,\,\,\,\,\,\,||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {C{H_3} - C - C{H_2}Cl \to } 
\end{array}}\limits_{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,II\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \)  \(\mathop {\begin{array}{*{20}{c}}
  {\,\,\,\,\,\,\,\,\,\,\,O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {\,\,\,\,\,\,\,\,\,\,||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {C{H_3} - C - CHC{l_2} \to } 
\end{array}}\limits_{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,III\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \) \(\mathop {\begin{array}{*{20}{c}}
  {\,\,\,\,\,\,\,\,\,\,\,\,\,\,O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {\,\,\,\,\,\,\,\,\,\,\,\,\,\,||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\ 
  {C{H_3} - C - CC{l_3}\,\,\,\,\,\,\,\,} 
\end{array}}\limits_{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,IV\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \)

\(\begin{matrix}
   \,\,O\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   \,\,||\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,  \\
   C{{H}_{3}}-C-CC{{l}_{3}}\xrightarrow{O{{H}^{-}}}  \\
\end{matrix}\) \(\begin{matrix}
   \begin{matrix}
   \,{{O}^{-}}  \\
   |\,\,\,\,  \\
\end{matrix}\,\,\,\,  \\
   C{{H}_{3}}-C-CC{{l}_{3}}\to   \\
   |\,\,\,\,\,\,\,  \\
   OH\,\,\,\,\,\,  \\
\end{matrix}\) \(\begin{array}{*{20}{c}}
  {\,\,\,\,\,\begin{array}{*{20}{c}}
  {\,\,\,\,\,O\,\,} \\ 
  {||} 
\end{array}\,\,\,\,\,\,\,} \\ 
  {C{H_3} - C - \mathop C\limits^ -  C{l_3}} \\ 
  {\,\,\,\,\,|\,\,\,\,\,\,\,\,} \\ 
  {\,\,\,\,\,\,\,\,\,\,OH\,\,\,\,\,\,\,} 
\end{array}\)