Which of the following reactions is an example of decomposition reaction?

\({\mathrm{H}}_{2}+{\mathrm{I}}_{2}\to 2\mathrm{HI}\)

\({\mathrm{NH}}_{4}\mathrm{CNO}\to {\mathrm{H}}_{2}{\mathrm{NCONH}}_{2}\)

\(\mathrm{NaOH}+\mathrm{HCl}\to \mathrm{NaCl}+{\mathrm{H}}_{2}\mathrm{O}\)

\(2{\mathrm{KClO}}_{3}\to \mathrm{KCl}+3{\mathrm{O}}_{2}\)