More is the percentage of s – character in a compound more nile be the electronegativity of central metal atom.
The hybridization of given compound will be as follows:–

• CO₃^2– has hybridisation of SP₂
• x_ef₄ has hybridisation of sp₃d₂
• I₃^– has hybridisation of s₃d
• Nal₃ has hybridisation of SP₃
• BeCl₂ has hybridisation of Sp as it has linear geometry.
  Lesser is the no. of porbital, more mill be percentage of s^–character.
  Hence correct increasing order of s-character is:–

x_eF⁴ < I₃ – NCl₃ < CO₃^2–< BeCl₂

Thus we can conclude that correct order of increasing s – character is:

 II < III < IV < I < V

Option (A) is correct