The conclusion that I have arrived at is this - however good the quiz is if there is a correct answer -"all of these" or similar, I shall rate the quiz as no better than average - quiz setters take your choice.

That is your privilege. You can rate on whatever basis you choose.

>"That is your privilege. You can rate on whatever basis you choose."

Ditto! And I reiterate that I do like that option occasionally. :-)