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 as SGA 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.
References:

References:https://docs.oracle.com/cd/B13789_01/server.101/b10734/rcmbackp.htm