Despite having an unpaired electron,the $ClO_2$ molecule does not undergo dimerization because .................

• A
  The unpaired electron is delocalized.
• B
  The unpaired electron is localized on the chlorine atom.
• C
  The bond lengths of the two $Cl-O$ bonds are not equal.
• D
  The chlorine atom possesses $p_x-p_x$ bonding.