HClO2>HClO4>HClO3>HOCl
HOCl>HClO2>HClO3>HClO4
HClO4>HClO3>HClO2>HOCl
HClO4>HOCl>HClO2>HClO3
Acidic strength∝Oxidation number
Increasing acid strength due to an increase in the oxidation state of the central atom.
HClO<HClO2<HClO3<HClO4
+1 +3 +5 +7
Hence, option A is correct.