Match the following.
\[ \begin{array}{|c|l|c|l|} \hline \text{List-I} & & \text{List-II} & \\ \hline \text{A} & \text{Prontosil} & \text{I} & \mathrm{-SO_2NH-} \\ \hline \text{B} & \text{Sulphapyridine} & \text{II} & \mathrm{-NHCOCHCl-} \\ \hline \text{C} & \text{Salvarsan} & \text{III} & \mathrm{-N=N-} \\ \hline & & \text{IV} & \mathrm{-As=As-} \\ \hline \end{array} \]
The correct answer is