Can someone please help me with this question?

6. Consider a diatomic molecule A-B with a ground-state wave function Do and corresponding ground state energy Eo. According to the variational principle, for any integral of the type Eave = Sy*Hydv Syp*wav (where ) is an arbitrary wave function) we have Eave2Eo Which of the following trial wavefunctions 1. y = GISA + C215 B 2. y = c , 2 s A + ( 2 25 B + C 3 2 PM + CA 2 P B + Cs2PM + Co2P,B + 62PM + C$2PxB 3. 4 = C, IsA + C215B + C325A + CA25B + Cs2PxA + Co2PxB + C, 2PM + C3 2 PyA + C, 2 Pz + C102 PzB + G,1 3SA + C12 35 B A) would have the most flexibility in representing a diatomic molecule such as nitrogen oxide N=O? points] B) would be the most difficult to compute in employing the MO-LCAO method? [6 points] C) employs the frozen core approximation? [6 points]