You are presented with the question "The pull of what on the Earth's oceans cause the tides?" and the following answer choices: 
- A yellow star
 - Time and energy
 - energy of moving objects
 - A natural satellite
 - flow of electrons
 - An artificial satellite
 - A red star
 - hydrogen and oxygen

Now knowing that the gravitational pull of the Moon on Earth 's oceans causes the tides and planetary moons are natural satellites, choose the best answer.


 

    A natural satellite     