I’d go with the “refuse to choose.” I actually remember this being an excercise in religious education class – while waffling a little bit about “each person must make their own choice,” the general implication was that the “right answer” is to refuse. The bad guy is a murderer (or will be in a few moments) but you can/should refuse to be an active participant in murder. And then be a passive martyr, I suppose.
With the dangling ropes – I’d try to grab the person on my right because I’m right-handed. I figure that would be my reflex anyway, to grab with my strong(er) hand.