Part of the emission spectrum for hydrogen in a laboratory shows two prominent lines at 410 nm410\text{ nm}410 nm and 434 nm434\text{ nm}434 nm. A spectrometer records spectra over the wavelength range of 400 nm400\text{ nm}400 nm to 450 nm450\text{ nm}450 nm.
An absorption spectrum of the same wavelength range is observed from Earth for light emitted by a galaxy moving away with a velocity of 0.040c0.040c0.040c.
Which of the following describes the lines visible in this observed absorption spectrum within the range of 400 nm400\text{ nm}400 nm to 450 nm450\text{ nm}450 nm?
Bright lines at 426 nm426\text{ nm}426 nm and 451 nm451\text{ nm}451 nm on a dark background.
Dark lines at 426 nm426\text{ nm}426 nm and 451 nm451\text{ nm}451 nm on a bright background.
A single bright line at 426 nm426\text{ nm}426 nm on a dark background.
A single dark line at 426 nm426\text{ nm}426 nm on a bright background.
