You are presented with the question "Unequal heating of Earth 's surface by what causes polar easterlies?" and the following answer choices: 
- sun
 - UV
 - drag
 - wind
 - loch
 - ovens
 - lightbulbs
 - blankets

Now knowing that unequal heating of Earth 's surface by the Sun causes global wind patterns and another major type of wind is called a polar easterly, choose the best answer.


 

 sun        