Which two statements are true about encrypting RMAN backup?

Which two statements are true about encrypting RMAN backup? (Choose two.)

A.
The transparent encryption of backups uses the encryption wallet

B.
The database uses the same encryption key for every encrypted backup

C.
The password encryption of backups only uses the password while creating and restoring backup

D.
If transparent encryption is configured, you cannot use the SET ENCRYPTION BY PASSWORD command to make password-protected backups.

Explanation:
http://www.di.unipi.it/~ghelli/didattica/bdldoc/B19306_01/backup.102/b14191/rcmbackp006.htm
A) Transparent Encryption of Backups
This is the default mode and uses the Oracle wallet. A wallet is a password-protected container used to store authentication and signing credentials, including private keys, certificates, and trusted certificates needed by SSL.

C) Password Encryption of Backups
This mode uses only password protection. You must provide a password when creating and restoring encrypted backups.

Dual Mode Encryption of Backups
Dual-mode encrypted backups can be restored either transparently or by specifying a password.  When restoring a dual-mode encrypted backup, you can use either the Oracle Encryption Wallet or a password for decryption.