Hugo Kornelis (3/21/2011)
Good question; superb explanation!I guess that if the author had included "all of the above" as a fifth answer option, the rate of incorrect answers would have been a lot higher. I guess that is the answer most respondents will first have in mind.
That would have been the option I selected. Or, if the question was one of those "Select All That Apply" and were check boxes instead of radio buttons I would have selected them all.