What does Rain-X primarily do?

Rain-X is designed to enhance driving visibility during inclement weather conditions, particularly when it comes to rainfall. Its primary function is to create a hydrophobic barrier on glass surfaces, which causes water to bead up and roll off the windshield. This action effectively repels rain, thereby improving visibility for the driver.

By promoting clearer sightlines while driving in the rain, Rain-X serves both to repel water as well as to enhance visibility. Thus, the function of repelling rain complements the overall purpose of improving visibility, making it clear why the correct response encompasses both aspects. This synergy not only enhances safety but also contributes to a more comfortable driving experience during adverse weather.