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.

First statement that says "The earth's moon is thought to have formed when a Mars-sized planet collided with Earth during its final stages of planetary accretion." 
I feel like this one is the only true sounding. 
"Without the earth's moon, life on Earth would not be possible" - false
"The earth's moon is the same size as the earth." - 1000% false, lol

Ibelieve the answer is c.