You are presented with the quiz "the mass of an object causes the what exerted by that object?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the mass of an object causes the gravitational force exerted by that object" and "all gravitational forces are attractive, there is no repulsive gravitational force". 

So, what's the best answer to the question?


 

   attractive force        