单项选择题An administrator migrates from AIX 5.3 to AIX 6.1. Upon completion, a client questions why files are missing from tmp. How should the administrator respond to the client?()
A.Explain that the files never existed in the first place.
B.Explain that during a Migration install the /tmp filesystem is overwritten.
C.Explain that after a Migration install, all system filesystems will be empty.
D.Explain that /tmp is temporary storage and files are automatically removed every 30 days.