You are presented with the question "Temperatures fall towards the poles as the sun's rays are no longer what?" and the following answer choices: 
- kinetic energy
 - negative
 - visible energy
 - harmful substances
 - perpendicular
 - heat energy
 - direct energy
 - reflecting light

Now knowing that temperature falls from the equator to the poles and sun's rays are perpendicular to the equator, choose the best answer.


 

     perpendicular    