Which three pieces of information are to be mandatorily provided while creating a new listener using Enterprise Manager Database Control?

Which three pieces of information are to be mandatorily provided while creating a new listener using Enterprise Manager Database Control? (Choose three.)

A.
the port used by the listener

B.
the database services to be registered with the listener

C.
the server name where the listener runs

D.
the log file and trace file destination for the listener

E.
the protocol used by the listener