Why might you prefer to shut down and then start up a Mac you are troubleshooting, rather than simply selecting Restart from the Apple menu?

A.
Because OS X loads a clean user session on startup only after a shutdown.

B.
Because OS X archives errors from the session to the log only during a shutdown.

C.
Because OS X performs disk checks on startup only after a shutdown.

D.
Because the Mac does a full POST on startup only after a shutdown.