简述记录器的功能。

A. The FRA disk group has an asynchronous I/O bottleneck
B. The least number of I/Os are performed on the last data file in the list
C. The number of times that the backup or restore process directed the OS to wait until an I/O was complete is the highest for the last data file in the list
D. The number of times that the backup or restore process made an OS call to poll for I/O completion in Nonblocking mode is the least for the FRA disk grou

A. 180°
B. 60°
C. 360°
D. 120°

A. 正确
B. 错误