单选题：Assume that,the page reference string as 2, 3, 2, 1, 5, 2, 4, 5,

Assume that,the page reference string as 2, 3, 2, 1, 5, 2, 4, 5, 3, 2, 5, 2; the system has 3 frames and all 3 frames are initially empty.
Optimal page replacement will have __________ page faults. @[B](1)
A. 5
B. 6
C. 7
D. 8




A.5
B.6
C.7
D.8


答案：B