Re: Quitting Emacs for buffer unassociated with file

[Richard Stallman]

    If a buffer has never been saved, there is no file to compare with it (and,
    a fortiori, no need for a comparison). The only options that make sense then
    are 1 and 2, and possibly 5 and 6.

The other options do make sense.  #3 is useful when the buffer
isn't selected.  #4 doesn't give you anything beyond what #3 gives you,
but it does make sense.