What must happen for a solar eclipse to occur?
a)the moon must pass behind earth.
b)the moon must be full.
c)the moon's orbit must cross the plane of the ecliptic.
d)the moon's orbit must not cross earth's penumbra.

The best answer to the question stated above is letter  C.The moon's orbit must cross the plane of the ecliptic.

>>Solar eclipses happen when the Moon moves between Sun and Earth, blocking the Sun's rays and casting a shadow on Earth.
>>Solar eclipses can happen only during a new Moon.
>>Earth's orbit is called the ecliptic plane as the Moon's orbit must cross this plane in order for an eclipse (both solar as well as lunar) to occur