David managed to accidentally delete the datafiles for database called DSL. He called Heber and Heber tried to help but he managed to delete the control files of the database. Heber called Bill and Bill saved the day. They are using a recovery catalog for this database. What steps did Bill perform to recover the database and in what order？（） a. Restored the control file with the RMAN restore controlfile command. b. Mounted the DSL instance with the alter database mount command. c. Restored the datafiles for the DSL database with the RMAN restore command. d. Opened the DSL database with the alter database open resetlogs command. e. Recovered the datafiles for the DSL database with the RMAN recover command. f. Started the DSL instance. g. Connected to the recovery catalog with RMAN.

A. a， b， c， d， e， f， g
B. b， c， d， g， f， e， a
C. g， f， a， b， c， e， d
D. c， a， d， b， f， e， g
E. g， f， a， b， e， c， d