Light, vision & weather

You start your car in daylight near Giethoorn; the daytime running light comes on automatically. Shortly after, you drive into a fog bank and switch on the fog light. What happens to the daytime running light?

Explanation

False — trap: assumption of simultaneous lighting. As soon as you switch on dipped beam, full beam or fog light, the daytime running light must switch off automatically (Book p.184).