If a Certain Gas Is Heated and Observed Through a Grating

Multiple Choice

If a certain gas is heated and observed through a grating, a bright line spectrum will be seen. If instead a source of continuous spectrum shines through a cooler sample of this same gas, a dark absorption spectrum is observed. How do the positions of the lines in these two spectra compare?

A) All the lines in the spectrum from the hot gas will be at higher frequencies than the corresponding lines in the spectrum of the cooler gas.
B) All the lines in the spectrum from the hot gas will be at lower frequencies than the corresponding lines in the spectrum of the cooler gas.
C) The lines in the two spectra will be at the same frequencies. They will be the same spectra.
D) These two processes produce spectra by completely different means, and there will be no relationship at all between the two spectra.