Which is the best sequence of reactions for the following transformation? i) HNO3,H2SO4; ii) NaBH4,H2O; iii) 2EtMgBr,Et2O i) LAH : ii) 2EtLi,Et2O; iii) HNO3,H2SO4, heat i) HNO3,H2SO4; ii) 2EtMgBr,Et2O; iii) NH4Cl i) 2EtMgBr,Et2O; ii) H3O+; iii) HNO3,H2SO4 None of these syntheses is satisfactory