单选题：consider a paging system with the page table stored in memory.If

consider a paging system with the page table stored in memory.If a memory reference takes 200 nanoseconds, how long does a paged memory reference take ?@[D](1)
A. 200 nanoseconds + the time to process the page entries which is a bit over 200 nanoseconds
B. depends, sometimes 400 nanoseconds, and sometimes 200 nanoseconds
C. 200 nanoseconds
D. 400 nanoseconds





A.200 nanoseconds + the time to process the page entries which is a bit over 200 nanoseconds
B.depends, sometimes 400 nanoseconds, and sometimes 200 nanoseconds
C.200 nanoseconds
D.400 nanoseconds


答案：D