单选题：A demand paging system adopts the LRU page replacement algorithm

A demand paging system adopts the LRU page replacement algorithm. Consider a reference string 1 8 1 7 8 2 7 2 1 8 3 8 2 1 3 1 7 1 3 7. Given four initially empty page frames, the total number of page faults is __________. @[B](1)
A. 4
B. 5
C. 6
D. 7




A.4
B.5
C.6
D.7


答案：B