A user receives the following error while executing a query： ORA/x7f01555：snapshot too old Which two options can be the solutions to avoid such errors in future？（）

• A、increase the size of redo log files
• B、increase the size of the undo tablespace
• C、increase the size of the Database Buffer Cache
• D、increase the size of the default temporary tablespace
• E、enable the retention guarantee for the undo tablespace