You are presented with the question "What causes earth's seasons?" and the following answer choices: 
- principals of aerodynamics
 - Physical weathering
 - floods
 - the tilt of the planet
 - an external framework
 - dry conditions
 - axis rotation
 - relative location

Now knowing that earth orbiting the Sun causes seasons to change and seasons are caused by the tilt of the axis relative to the planet's orbit, choose the best answer.


 

    the tilt of the planet     