Given: Two statements are to be checked for correctness.
Find: Which option correctly describes Statement I and Statement II.
Statement I: SbCl5 is more covalent than SbCl3.
According to Fajan's rules, a higher oxidation state of the central atom causes greater polarization of the anion and hence greater covalent character. Antimony is in the +5 oxidation state in SbCl5 and in the +3 oxidation state in SbCl3. Therefore, SbCl5 is more covalent than SbCl3.
Statement II: The higher oxides of halogens tend to be more stable than the lower ones.
This is also correct. Higher oxides of halogens are generally more stable because of greater covalent character and stronger bonding. For example, Cl2O7 is more stable than Cl2O.
Therefore, both Statement I and Statement II are correct. The correct option is A.