Based on data from the U. S. Census Bureau, a Pew Research study showed that the percentage of employed individuals ages 25-29 who are college educated is at an all-time high. The study showed that the percentage of employed individuals aged 25-29 with at least a bachelor's degree in 2016 was 40%. In the year 2000, this percentage was 32%, in 1985 it was 25%, and in 1964 it was only 16%.+ What is the population being studied in each of the four years?
a. college educated individuals
b. college educated individuals aged 25-29
c. individuals aged 25-29
d. employed individuals aged 25-29
e. employed individuals