单选题

A disk scheduling mechanism in an operating system causes the disk arm to sweepbackand forth across the disk Surface servicing all requests in its path. This is a (73) .

A、 First Come First Serve
B、 Shortest Seek Time First
C、 Scan
D、 None of the above

【正确答案】 C

【答案解析】[解析] 译文：操作系统的磁盘调度机制引起磁盘臂在磁盘表面前后掠动，这叫作扫描。