You are presented with the quiz "The mass of a planet causes the pulling force that does what?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "the mass of a planet causes the pull of gravity on that planet" and "gravity is the pulling force that holds objects to the surface of a planet". 

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


 

 holds objects to its surface          