Does anybody know this

In the developed world, women are increasingly more likely to delay childbirth until their mid- to late- twenties or long because

Find the area of the shaded region.

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted