单项选择题In your running instance, some of the initialization parameters are set as shown below: SGA_MAX_SIZE = 14GB DB_CACHE_SIZE = 1GB SHARED_POOL_SIZE = 3GB STATISTICS_LEVEL = BASIC PGA_AGGREGATE_TARGET = 0 You plan to enable Automatic Shared Memory Management but you are not able to set SGA_TARGET to a nonzero value. What could be the reason?()
A.The STATISTICS_LEVEL initialization parameter is set to BASIC
B.The PGA_AGGREGATE_TARGET initialization parameter is set to zero.
C.The SGA_MAX_SIZE initialization parameter is set to less than 20 GB
D.The DB_CACHE_SIZE initialization parameter is set to less than 5 GB
E.The SHARED_POOL_SIZE initialization parameter is set to a nonzero value.