When performing a full database disaster recovery with RMAN， in what order would you execute these steps？（）  
a. Restore the control file from autobackups. 
b. Run the RMAN restore and recover command. 
c.Restore the database spfile from autobackups. 
d. Make the RMAN backup set pieces available. 
e. Open the database with the alter database open resetlogs command. 
f.Open the database with the alter database open command. 

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