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

AThe database instance starts, and Oracle sets the default value of SGA_TARGET to the same value as SGA_MAX_SIZE

BThe database instance starts, and Oracle automatically tunes memory and allocates 60 percent to the SGA and 40 percent to the PGA

CThe database instance starts, but Automatic Memory Management is disabled

DThe database instance will not start because you did not specify the PGA_AGGREGATE_TARGET or SGA_TARGET parameter