The correct sequential order of the reagents for the given reaction is
\( \mathrm{HNO_2} \), \( \mathrm{Fe/H^+} \), \( \mathrm{HNO_2} \), \( \mathrm{KI} \), \( \mathrm{H_2O} \)/\( \mathrm{H^+} \)
\( \mathrm{HNO_2} \), \( \mathrm{KI} \), \( \mathrm{Fe/H^+} \), \( \mathrm{HNO_2} \), \( \mathrm{H_2O} \)/warm
\( \mathrm{HNO_2} \), \( \mathrm{KI} \), , \( \mathrm{HNO_2} \), \( \mathrm{Fe/H^+} \), \( \mathrm{H_2O} \)/\( \mathrm{H^+} \)
\( \mathrm{HNO_2} \), \( \mathrm{Fe/H^+} \), \( \mathrm{KI} \), \( \mathrm{HNO_2} \), \( \mathrm{H_2O} \)/warm