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.