The Dark Absorption Lines in the Solar Spectrum Are Caused

Multiple Choice

The dark absorption lines in the solar spectrum are caused by

A) a cooler layer of gas overlying the hot solar surface, which contains many elements, including hydrogen, helium, magnesium, calcium, and iron.
B) a cooler layer overlying the hot solar surface, consisting solely of hydrogen gas, which produces all the absorption lines.
C) absorption by atoms and molecules in Earth's cool atmosphere.
D) a hotter layer of gas that overlies the cooler solar surface and produces the absorption lines.