A disk scheduling mechanism in an operatingsystem causes the disk arm to sweepback and forth across the disk surface servicing all requests in its path. This is a

A． First Come First Serve

B． Shortest Seek Time First

C． Scan

D． None of the above

下列属于期货公司董事、监事和高级管理人员任职条件的有（）。

A.诚实守信的品质

B.良好的职业道德

C.履行职责所必需的经营管理能力

D.具有硕士研究生以上学历