EDIT Ok so it’s just the trolly problem.
EDIT2 : AHA War Games 1983. “The only winning move is not to play.” (We might call this the final product of a lot of smart philosophical digestion, because it’s a famous movie). There’s always the perfectly valid option to ditch the riddle. (Because maybe the riddle is dumb, or maybe the riddle is no better than a thousand others, utilitywise )
If you want a serious answer ask a serious question. Not an absurd and ghoulish hypothetical.