You said: D.) A & B

Yes, that's absolutely right.

Before securing the area, you need to check around to see if anyone is still there. Was that computer left on by mistake or is someone still working there?

If you are reasonably sure that you are the last one out for the day, then you can close the area according to procedure.

Oh yes...if you did happen to have a coffee pot running you should turn it off!
Now, we are going to look at some issues concerning document management....