You are presented with the question "What can cause the speed of an object to decrease?" and the following answer choices: 
- more propulsion
 - a tree falling
 - degrees Celsius
 - degrees celcius
 - texture of the surfaces
 - inertia
 - Electrical energy
 - sunlight

Now knowing that friction causes the speed of an object to decrease and friction is dependant on the texture of both surfaces, choose the best answer.


 

     texture of the surfaces    