Which statement best explains why nitric oxide (NO) cannot satisfy the octet rule for both atoms in any valid Lewis structure?
a) Forming the double or triple bonds needed to satisfy both octets would give oxygen a positive formal charge, which is too unstable, so the molecule adopts an electron-deficient structure instead.
b) The molecule possesses an odd total number of valence electrons, leaving one electron unpaired regardless of bonding arrangement.
c) Nitrogen lacks vacant d-orbitals and therefore cannot expand its valence shell beyond eight electrons.
d) Because oxygen is more electronegative than nitrogen, it must retain its lone-pair electrons, leaving too few electrons to complete nitrogen’s octet.