You are presented with the question "What does gravitational pull of the moon cause?" and the following answer choices: 
- tides
 - waves
 - heat
 - gravitational pull of the sun
 - rain
 - the world's orbit
 - motion
 - erosion

Now knowing that the gravitational pull of the Moon on Earth 's oceans causes the tides and earth Day celebrations are now held across the world, choose the best answer.


 

 tides        