The DBA has chosen to manage SGA and PGA memory separately in an OLTP database because of his unique knowledge of the application. Which of these are good starting points to use when configuring the maximum values for SGA and PGA，based on the amount of memory available on the system？（）

A、 20% SGA 80% PGA

B、 25% SGA 75% PGA

C、 50% SGA 50% PGA

D、 75% SGA 25% PGA

E、 80% SGA 20% PGA