Propose an efficient synthesis for the following transformation: The transformation above can be performed with some reagent or combination of the reagents listed below. Give the necessary reagent(s) in the correct order, as a string of letters (without spaces or punctuation, such as "EBF"). If there is more than one corre solution, provide just one answer. A B C D t-BuOK 1) MeMgBr, 2) H3O Na2Cr2O7,H2SO4,H2O NaOH E F G H2, Lindlar's cat. H2,Pt TsCl.py dilute H2SO4 1 K L 1) LiAlH4 : 2) H3O+ DMP or PCC 1) EtMgBr; 2) H3O+ 1) BH2 THF: 2) H2O2,NaOH