Explanation
Explanation/Reference:
References: https://docs.oracle.com/database/121/LADBI/oraclerestart.htm#LADBI999

Explanation
A:
1. Get the list of all datafiles.
Note: RMAN Backup of ASM Storage
There is often a need to move the files from the file system to the ASM storage and vice versa. This may come in handy when one of the file systems is corrupted by some means and then the file may need to be moved to the other file system.
D: Migrating a Database into ASM
* To take advantage of Automatic Storage Management with an existing database you must migrate that database into ASM. This migration is performed using Recovery Manager (RMAN) even if you are not using RMAN for your primary backup and recovery strategy.
* Example:
Back up your database files as copies to the ASM disk group.
BACKUP AS COPY INCREMENTAL LEVEL 0 DATABASE
FORMAT '+DISK' TAG 'ORA_ASM_MIGRATION';
References:

B:
* A PDB would have its SYSTEM, SYSAUX, TEMP tablespaces. It can also contains other user created tablespaces in it.
* There is one default temporary tablespace for the entire CDB. However, you can create additional temporary tablespaces in individual PDBs.
D:
* There is a single redo log and a single control file for an entire CDB
* A log switch is the point at which the database stops writing to one redo log file and begins writing to another. Normally, a log switch occurs when the current redo log file is completely filled and writing must continue to the next redo log file.
G: instance recovery
The automatic application of redo log records to uncommitted data blocks when an database instance is restarted after a failure.
Incorrect:
Not A:
* There is one set of background processes shared by the root and all PDBs.
* High consolidation density. The many pluggable databases in a single container database share its memory and background processes, letting you operate many more pluggable databases on a particular platform than you can single databases that use the old architecture.
Not C: There is a separate SYSAUX tablespace for the root and for each PDB.
Not F: There is a separate SYSTEM tablespace for the root and for each PDB.