Answer the following question given this paragraph: 

Weather is always changing. One day might be cold and cloudy. The next day might be warm and sunny. Even on the same day, the weather can change a lot. A beautiful morning might be followed by a stormy afternoon. Why does weather change? The main reason is moving air masses.


Q: What is the main reason for weather change?

 Choices:

- climate change

- moving energy masses

- seasons

- moving air masses

A:
moving air masses
