It's a movie reference. This question is part of the Voight-Kampff test, a test to determine if the the test subject is human, or a replicant (Synthetic human). It appears in the movie Bladerunner.
(I can't remember if it is also part of the book).
(I can't remember if it is also part of the book).
Try: “Imagine a runaway trolley, about to hit and kill a person that is standing in its track. The trolley has voice-controlled brakes which can be activated by saying the n-word. Is it okay to say the n-word to stop the trolley and save a life?”