You are presented with the question "The mass of an object causes _." and the following answer choices: 
- heat is produced
 - kinetic energy
 - It gets heated up
 - a constant impelling force
 - a tree falling
 - a lot of human deaths
 - principals of aerodynamics
 - body temperature reduces

Now knowing that the mass of an object causes the gravitational force exerted by that object and gravitation is a constant impelling force, choose the best answer.


 

    a constant impelling force     