The order of heat of hydrogenation in following compound is :

$\mathrm{Heat}\mathrm{\hspace{0.17em}\hspace{0.17em}}\mathrm{of}\mathrm{\hspace{0.17em}\hspace{0.17em}}\mathrm{hydrogenation}\mathrm{\hspace{0.17em}\hspace{0.17em}}\propto \mathrm{\hspace{0.17em}\hspace{0.17em}}\frac{1}{\mathrm{stability}\mathrm{\hspace{0.17em}\hspace{0.17em}}\mathrm{of}\mathrm{\hspace{0.17em}\hspace{0.17em}}\mathrm{alkene}}$

(III) is more stable due to the presence of Resonance and hyperconjugation

(IV) Stability is due to Resonance.

(II) Stability is due to hyperconjugation.

(I) no hyperconjugation and no Resonance.

$\therefore$order of stability is III > IV > II > I