26. Which of the following statement is correct?
(A) Back bonding concerns the electron donation coming from ligands to metal and yielding sigma bond
(B) HOMO has higher energy levels than LUMO in molecular orbital theory
(C) Compared to Lewis structure, molecular orbital theory describes bonding electrons to be more delocalized
(D) The larger radius ratios of cation to anion (R_cation/R_anion), the smaller coordination numbers observed in the crystal packing

(E) None of the above