You are presented with the question "Warm air advancing on what causes cloudy and rainy weather?" and the following answer choices: 
- streams.
 - streams
 - Movement
 - flooding
 - coastlines
 - rivers
 - rainfall
 - cold air

Now knowing that awarm front causes cloudy and rainy weather and if warm air is advancing on cold air, the front is designated a warm front, choose the best answer.


 

        cold air 