Fact 1: Awarm front causes cloudy and rainy weather.

Fact 2: If warm air is advancing on cold air, the front is designated a warm front.

Given the two facts above, answer the question "Warm air advancing on what causes cloudy and rainy weather?" with the following options: 
- streams.
 - streams
 - Movement
 - flooding
 - coastlines
 - rivers
 - rainfall
 - cold air


 

        cold air 