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.