单选题：The evolution of operating systems for mainframes is roughly lik

The evolution of operating systems for mainframes is roughly like from __________. @[D](1)
A. no software -> multi-programming-> multi-tasking
B. no software -> multi-tasking -> multi-programming
C. no software->  resident monitors -> multi-tasking-> multi-programming
D. no software -> resident monitors -> multi-programming->multi-tasking





A.no software -> multi-programming-> multi-tasking
B.no software -> multi-tasking -> multi-programming
C.no software->  resident monitors -> multi-tasking-> multi-programming
D.no software -> resident monitors -> multi-programming->multi-tasking


答案：D