Fact 1: The gravitational pull of the Moon on Earth 's oceans causes the tides.

Fact 2: For example, ocean tides are caused by the sun and moon's gravity pulling on the water.

Given the two facts above, answer the question "What causes tides?" with the following options: 
- waves
 - sunlight
 - Mass
 - moon
 - weight
 - force
 - wind
 - asteroid


 

    moon     