$(A)$ a smaller cation : High charge density results in more attraction for the bond pair of electrons.
$(B)$ a larger anion : Low charge density results in less attraction for the bond pair of electrons.
$(C)$ large charges on cation or anion : With increase in the charge, the electrostatic attraction between cation and the bond pair of electrons increases.
$B _{2}, Li _{2}, C _{2}, C _{2}^{-}, O _{2}^{2-}, O _{2}^{+}$ અને $He _{2}^{+}$