Statement I : Since HClO4 is a stronger acid than H2SO4, HCl and HNO3,and therefore it has a greater tendency to donate proton in comparison to others.
Statement II : Perchloric acid is stronger acid than H2SO4 in acetic acid.
Perchloric acid will have a more stable conjugate base in acetic acid due to greater extent resonance in the conjugate base. Question is based on the levelling effect of water. Only H+ can exist as a strong acid in water.