Which three statements correctly describe the features of the I/O calibration process？（）

• A、 Only one I/O calibration process can run at a time
• B、 It automates the resource allocation for the Automated Maintenance Tasks
• C、 It improves the performance of the performance-critical sessions while running
• D、 It can be used to estimate the maximum number of I/Os and maximum latency time for the system
• E、 The latency time is computed only when the TIMED_STATISTICS initialization parameter is set to TRUE