These quizzes are very ool but not that easy to play. Do you think that you could use a command to make the guessed answered overally green, and not just the cell, for a greater visibility, as it's the case on some other quizzes of this sort? I can't send the command I've in mind in a comment but I guess you understand what I mean.
My theory on Bach is that when people are guessing, they're more likely to guess one of the "old-timey" ones because the modern ones they're more likely to actually recognize. Bach may just be the least recognized of the old-timey wrong options (except perhaps for Rembrandt, but c'mon, that hat is just a dead giveaway that this dude was never president).