If a Continuous Spectrum of Ultraviolet Radiation Passes Through a Tube

Multiple Choice

If a continuous spectrum of ultraviolet radiation passes through a tube of cool hydrogen gas, what happens to its spectrum?

A) All the radiation passes unhindered except the Lyman L _$\alpha$ wavelength, which is absorbed by the atoms.
B) Some of the radiation at all wavelengths is absorbed, reducing the intensity at all wavelengths uniformly.
C) All the radiation passes through the tube unhindered because the hydrogen gas is cool and cannot absorb energy.
D) All the radiation passes through the tube unhindered except at the specific wavelengths of the Lyman series, L _$\alpha$ , L _{$\beta$ ,} and so on, which are absorbed by the atoms.