#trappist-1d

I’m guessing you’d have to choose the right path?  I’ve never taken the problem seriously, but, in principle, it’s a standard problem that’s often dealt with by some sort of computer program.

To take the trolley problem from the example, you know there’s a guy on a track with a switch.  The guy has two doors: they both have a nice yellow button next to them (you could just as easily pick a red or blue button for the switches).  On the track are some levers that you can push to either flip the guy over onto the other side of the track, or pull the lever that stops the train.

Here’s the tricky bit: you can’t choose any of the two doors.  You can push either the red or the blue button, but you can’t push both at once.

The reason for this is that the train could run forward indefinitely, even if there’s a second guy on the track, and the first guy will die if you push the red button, but it wouldn’t kill the train because it’s going forward anyway.  (This does not mean you can’t do anything to the train that’s not pushing the buttons – I’ve seen people do things like hitting the dead guy with a fire extinguisher to stop it from moving, which might stop the train, but is in fact completely useless.)  In principle, you could predict that pushing both buttons would send the train running forward forever.