According to Fajan's Rule, small cation has more polarising power and larger anion has more polarisability. These small cations and larger anions favours covalent character.
A. KF>KI−False (Iodide is larger anion than fluoride)
LiF>KF−True (Lithium-ion is smaller cation than potassium ion)
B. KF<KI−True; LiF>KF−True
C. SnCl4>SnCl2−True(Sn4+ is smaller than Sn2+);
The ions with pseudo inert gas configuration prefers the covalent character.
CuCl>NaCl−True(Cu+(3s23p63d10) ion has pseudo inert gas configuration)
D. LiF>KF−True; CuCl<NaCl−False
E. KF<KI−True; CuCl>NaCl−True