d
The value of \(\Delta T_b\) depends upon two factors \('i'\) and \('m'\). It is given that \(1\,mol\) of each compound is dissolved in \(1\,L\) of solution. Hence molarity is same foe all the comounds. Noe the van't Hoff factor depends on number of particle i.e. on degree of ionisation which further depends on the bond dissociation energy which is in the order

\(HI < HBr < HCl < HF\)

i.e. bond dissociation energy of \(HI\) is least. Lower the bond dissociation energy, higher is the degree of ionisation and hence higher the number of particles, thus \(i\) will be maximum for \(HI\) and hence \(\Delta T_b\) value will be larger for \(HI\).