Part of the Current Atmosphere of Earth Is Believed to Be

Multiple Choice

Part of the current atmosphere of Earth is believed to be

A) the remnants of the original hydrogen and helium gas from the solar nebula attracted by the protoplanet.
B) the result of the melting and vaporizing of the glaciers from the last ice age.
C) composed primarily of hydrogen and helium.
D) composed of gases that were outgassed from the heated rocks sometime after the planet formed.
E) the result of a collision between the Sun and another star.