C

Step 1: Understand the concepts of emission and absorption spectra.
The emission line spectrum occurs when electrons in an atom return to a lower energy level and emit a photon of light. The wavelength of this emitted light is characteristic of the element.
Step 2: In an absorption line spectrum, electrons absorb energy and move from a lower to a higher energy level, resulting in dark lines at specific wavelengths where light is absorbed.
Step 3: The wavelengths corresponding to the absorption lines are the same as those of the emission lines because they represent the same energy transitions.
Therefore, absorption and emission spectra are directly related: for each transition energy, the absorbed and emitted wavelengths are equal.
Therefore, the correct answer is option C: They are equal.