Can we draw the following hypothesis from the context (see options)? 

Context:

Stokes shift is the difference (in wavelength or frequency units) between positions of the band maxima of the absorption and emission spectra (fluorescence and Raman being two examples) of the same electronic transition. It is named after Irish physicist George G. Stokes.

Hypothesis: stokes shift has 2 possible units 
pick from the following.
* Yes
* It's impossible to say
* No