Which of the following commands must be issued to remove a stored script from the recovery catalog？（）

A.It helps you to determine whether or not the Oracle database is running.
B.It requires the username and password to check the connectivity of the service.
C.It does not require the username and password to check the connectivity of the service.
D.It establishes a session with the database and checks the connectivity of the service.

A.PMON
B.SMON
C.CKPT
D.LGWR
E.ARCn

A.ROWS
B.SKIP
C.LOAD
D.BINDSIZE