You started a long transaction. Before committing， you executed a query on one of the tables currently being modified. You received the following error： ORA-01555： snapshot too old How would you prevent such an error in the future？（）

A. guarantee undo retention
B. add one more redo log group
C. size the redo log files appropriately
D. size the UNDO tablespace appropriately
E. size the SYSTEM tablespace appropriately
F. configure an appropriate undo retention interval
G. change automatic undo management to manual