A: PGA itself is subdivided. The UGA (User Global Area) contains session state information, including stuff like package-level variables, cursor state, etc. Note that, with shared server, the UGA is in the SGA. It has to be, because shared server means that the session state needs to be accessible to all server processes, as any one of them could be assigned a particular session.
However, with dedicated server (which likely what you're using), the UGA is allocated in the PGA.
C: The Location of a private SQL area depends on the type of connection established for a session. If a session is connected through a dedicated server, private SQL areas are located in the server process' PGA. However, if a session is connected through a shared server, part of the private SQL area is kept in the SGA.
Note:
*System global area (SGA)
The SGA is a group of shared memory structures, known asSGA components, that contain data and control information for one Oracle Database instance. The SGA is shared by all server and background processes. Examples of data stored in the SGA include cached data blocks and shared SQL areas.
* Program global area (PGA)
A PGA is a memory region that contains data and control information for a server process. It is nonshared memory created by Oracle Database when a server process is started. Access to the PGA is exclusive to the server process. There is one PGA for each server process. Background processes also allocate their own PGAs. The total memory used by all individual PGAs is known as the total instance PGA memory, and the collection of individual PGAs is referred to as the total instance PGA, or just instance PGA. You use database initialization parameters to set the size of the instance PGA, not individual PGAs.

* From the exhibit we see that FORCE_LOGGING is set to NO.
* Datapump Import impdp in 12c includes a new parameter to disable logging during data import. This option could improve performance of import tremendously during large data loads.
The TRANSFORM=DISABLE_ARCHIVE_LOGGING is used to disable logging. The value can be Y or N.
Y to disable logging and N to enable logging.
However, if the database is running with FORCE LOGGING enabled, data pump ignores disable logging request.
Note:
*When the primary database is in FORCE LOGGING mode, all database data changes are logged. FORCE LOGGING mode ensures that the standby database remains consistent with the primary database.
*force_logging V$database
A tablespace or the entire database is either in force logging or no force logging mode. To see
which it is, run:
SQL> SELECT force_logging FROM v$database;
FOR
NO

Explanation/Reference:
Explanation:
Service registration enables the listener to determine whether a database service and its service handlers are available. A service handler is a dedicated server process or dispatcher that acts as a connection point to a database. During registration, the LREG process provides the listener with the instance name, database service names, and the type and addresses of service handlers. This information enables the listener to start a service handler when a client request arrives.