You specify a nonzero value for the MEMORY_TARGET initialization parameter, but do not set thePGA_AGGREGATE_TARGET or the SGA_TARGET parameters. You restart your database instance.Which statement about the result is true?（）

• A、The database instance starts, and Oracle sets the default value of SGA_TARGET to the same value as SGA_MAX_SIZE
• B、The database instance starts, and Oracle automatically tunes memory and allocates 60 percent to the SGA and 40 percent to the PGA
• C、The database instance starts, but Automatic Memory Management is disabled
• D、The database instance will not start because you did not specify the PGA_AGGREGATE_TARGET or SGA_TARGET parameter