The Newly-Formed Earth's Atmosphere Was Very Different from Earth's Current

The newly-formed Earth's atmosphere was very different from Earth's current atmosphere because it had ____.

A) an abundance of mercury vapor
B) an enormous amount of carbon dioxide, resulting in very hot temperatures due to greenhouse effect
C) virtually no oxygen, a necessary component for the existence of animal life
D) an enormous amount of methane and ammonia, which was never lost by the atmospheres of the outer planets
E) virtually no nitrogen, the major component of today's atmosphere