单选题：Assume that a main memory access takes 100 ns. If we are using a

Assume that a main memory access takes 100 ns. If we are using a two-level page table and have a 50% TLB hit ratio, the effective memory access time is (assume no TLB and no page faults access time): @[C](1)
A. 400 ns
B. 300 ns
C. 200 ns
D. 100 ns




A.400 ns
B.300 ns
C.200 ns
D.100 ns


答案：C