Statement I: Increasing order of acidity of hydrogen halides is HF < HCI < HBr < HI.
Statement II: While comparing acids formed by the elements belonging to the same group of the periodic table, H-A bond strength is a more important factor in determining acidity of an acid than the polar nature of the bond. HI bond is weaker than other halides, so lesser bond dissociation energy and more acidic nature.
Both statements I and II are correct. Statement II is the explanation of statement I.