Which Statement About Earth Is TRUE

Which statement about Earth is TRUE?

A) The oxygen in Earth's atmosphere was created by the evaporation of seawater and its dissociation into hydrogen and oxygen by solar UV light.
B) Earth has always had an oxygen-rich atmosphere, which was one reason that life could develop on Earth.
C) Out-gassing by volcanic eruptions converted the carbon-dioxide-rich atmosphere into an oxygen-rich atmosphere, thus creating conditions in which life could develop.
D) Life developed in a carbon-dioxide-rich atmosphere and then converted it into an oxygen-rich atmosphere.