Read this sentence from The Evolution of Useful Things.Making waterproof sandpaper would allow wet sanding, which in turn would cut down on dust, and thus be a great improvement.

The sentence links each result to what causes it: waterproof sandpaper would allow wet sanding, and wet sanding would reduce dust. The phrase “which in turn” signals this cause-and-effect relationship. So the best choice is “a cause-and-effect relationship.”

AI-written and checked against the verified answer.