Neutralisation is the reaction between an acid and a base to form a salt and water.
The reaction of an aqueous hydrochloric acid solution with an aqueous sodium hydroxide solution is represented by the neutralization chemical equation
$HCl(aq) + NaOH(aq) → NaCl(aq) + H_2O(l) + heat$
The heat of neutralization is highest in $HCl+NaOH$
Hence c is the correct answer.
