Your database is up and running and one of your three control files is accidentally erased. You start RMAN and run the following command：   RESTORE CONTROLFILE FROM AUTOBACKUP；   Which of the following statements is true？（） 

A. The command restores only the missing control file.

B. The command restores all the control files.

C. The command fails because the database is running.

D. This is the correct way to address this problem.

E. This is not the correct way to address this problem.