the Sun the Moon asteroids comets
I gave my students this multiple choice question: Miriam notices when she goes to the beach that sometimes the water rises as high as the pier. At other times of the day, the water barely covers the pillars under the pier. These differences in water level are primarily due to the gravitational influence of which of the following?

Only one answer is correct among these 4 choices:
- the Sun
- the Moon
- asteroids
- comets

Could you tell me which one is correct?

the Moon