Using the Graphic Below, What Is the Primary Difference Between

Using the graphic below, what is the primary difference between the populations of Iowa and Texas?

A) The population of Iowa is older.
B) Texas has a much lower birth rate.
C) The influx of immigrants into Iowa is making the population younger.
D) Texas has a higher percentage of both older males and females.
E) There is no difference: the populations of the two states are nearly identical.