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 "EBF7). If there is more than one correct solution, provide just one answer. A. B C D. t-BuOK H2,PtNa2Cr2O2,H2SO4H2O 6. MeONa H2 tindiar's cat. 1) 0,21DM5 Tscl. pr ditute H2SO4