In which of the following options order of arrangement  does not agree with the variation of property indicated against it?(I) Al3+  <  Mg2+  <  Na+  <  F−  (Increasing ionic size)(II) B < C < N < O (Increasing first ionisation enthalpy)(III) I < Br < Cl < F (Increasing electron gain enthalpy)(IV) Li < Na < K < Rb (Increasing metallic radius)