一道关于分子轨道的英文题What is the most important extra step that has t

一道关于分子轨道的英文题
What is the most important extra step that has to be included in the first approach technique for assigning electrons in a heteronuclear diatomic molecule?
A Account for the effect of anti-bonding electron orbitals.
B Account for any hybridization effects.
C Account for the orbital energy differences between the two atoms.
D Account for the electronegativity (and orbital energy) differences between the two atoms.