The Emission Spectrum of an Element Is

The emission spectrum of an element is:

A) The spectrum given off by a heated gas when its excited electrons release photons
B) The spectrum observed from a cool gas, where black lines on the spectrum indicate photons used to excite electrons
C) The spectrum given off by a cool gas when its excited electrons release photons
D) The spectrum observed from a heated gas, where black lines on the spectrum indicate photons used to excite electrons.
E) The range of gases emitted during a chemical reaction.