You are working on a test database where instance recovery takes a considerable amount of time.How can reduce the recovery time？（）

• A、By multiplexing the control files
• B、By multiplexing the redo log files
• C、By decreasing the size of redo log files
• D、By configuring mean time to recover （MTTR） to a lower value
• E、By setting the UNDO_RETENTION parameter to a higher value