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).
Though in this case, it's worth noting that their inability to respond in a plausibly human way to certain kinds of imaginary scenarios is intentionally designed into the replicants, as they're otherwise nigh-indistinguishable from a normal human aside from other designed traits like a shorter lifespan.
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?”
It's a blade runner reference. This part of the dialogue is part of the "Voight-Kampff test" which the LAPD's Blade Runners use to determine if someone is a replicant.
