upper atmospheric disturbances. the tilt of Earth's rotational axis. density differences caused by temperature changes. the gravitational pull of the Sun and the Moon.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Tides occur in the oceans at regular times every day because of
Possibilities:
- upper atmospheric disturbances.
- the tilt of Earth's rotational axis.
- density differences caused by temperature changes.
- the gravitational pull of the Sun and the Moon.

the gravitational pull of the Sun and the Moon.