Which statement is true?

The earth's moon is thought to have formed when a Mars-sized planet collided with Earth during its final stages of planetary accretion.
Without the earth's moon, life on Earth would not be possible.
The earth's moon is the smallest moon relative to its host planet.
The earth's moon is the same size as the earth.

Question

Which statement is true?

The earth's moon is thought to have formed when a Mars-sized planet collided with Earth during its final stages of planetary accretion.
Without the earth's moon, life on Earth would not be possible.
The earth's moon is the smallest moon relative to its host planet.
The earth's moon is the same size as the earth.

anonymous · Answer

help on a quiz

supernova_sonntag · Answer

I would say the first one. 
Life is not solely dependent on the moon, the next one just isn't true (it is Pluto's moon Charon), and the moon is obviously smaller than the Earth.

supernova_sonntag · Answer

Given life would be hard without a moon, but there could still be some.