A trolley is heading towards 4 people. If you pull the switch, it will be diverted towards 1 person. Also, if you slip the switch by pulling it after the front wheels have passed but before back wheels do, it will probably come to a complete halt before hitting anyone, but there is a 20% chance that you'll fuck up and kill all 5 people. There are exits to the east, north, west, and south.
Congratulations, the trolley has derailed, crashing into the ground between the two groups of tied up people. All the passengers inside the trolley are now dead.
This has always been my option. Derail the train, if there is a moral choice it is to do everything you can to stop the trolley and failing that is the only guiltless choice.
If you tried a third option over the two choices given then you can't feel guilty if the third option doesn't work.