Which of the following is the proper order of addition of reagents in Vial A prior to quenching with methanol? A. R-HBTM → unknown alcohol → butyric anhydride + Et3N B. unknown alcohol → R-HBTM → butyric anhydride + Et3N C. S-HBTM → unknown alcohol → butyric anhydride + Et3N D. unknown alcohol → butyric anhydride + Et3N → S-HBTM E. unknown alcohol → S-HBTM → butyric anhydride + Et3N F. unknown alcohol → butyric anhydride + Et3N → R-HBTM