Dana Medley (12/19/2013)
Great question Steve. I had it right to begin with, then I second guessed myself. Should've stuck with my original answer.
That's exactly where I went wrong - changed right to wrong.
Now if the number of boxes to tick had been there I wouln't have added clustering to the two correct options. Leaving the number to tick out of teh question definitely improves it, because one needs to know the answer to get it right.