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?（）

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