the Moon blocks the Earth from the Sun. the first four planets in the solar system are aligned. Earth blocks the Moon from the Sun. Earth's shadow falls on the Sun.
I gave my students this multiple choice question: A solar eclipse occurs when

Only one answer is correct among these 4 choices:
- the Moon blocks the Earth from the Sun.
- the first four planets in the solar system are aligned.
- Earth blocks the Moon from the Sun.
- Earth's shadow falls on the Sun.

Could you tell me which one is correct?

the Moon blocks the Earth from the Sun.