Which two statements are true?

Your database instance has the following parameter setting:
OS_AUTHENT_PREFIX = OPS$
You execute the following command:

And then grant OPS$GUEST_USER the CREATE SESSION privilege.
Which two statements are true?

Your database instance has the following parameter setting:
OS_AUTHENT_PREFIX = OPS$
You execute the following command:

And then grant OPS$GUEST_USER the CREATE SESSION privilege.
Which two statements are true?

A.
GUEST_USER can query the tables created in the USERS tablespace by default.

B.
The authentication details for GUEST_USER are stored in the database password file.

C.
A local GUEST_USER OS account should exist before GUEST_USER can log on to the database.

D.
GUEST_USER can log on to the database without specifying a username and password.

E.
GUEST_USER is forced to change the password at the first login.