Earth formed around 4.54 billion years ago by accretion<span> from the </span>solar nebula.<span> Volcanic </span>outgassing<span> probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no </span>oxygen<span> and so would have been toxic to most modern life including humans. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. A "giant impact" collision with a planet-sized body is thought to have been responsible for forming the Moon. Over time, the Earth cooled, causing the formation of a solid </span>crust<span>, and allowing liquid water to exist on the surface.
"<span>D)the emperor and religious leaders of the Byzantine Empire refused to accept the authority of the pope" is the best option since this caused the most havoc. </span>
