Sarah Is Designing an International Study of the Effect of Age

Sarah is designing an international study of the effect of age composition on voting behaviors.After deciding to compare older,middle-aged,and young nations on rates of voting in national-level elections,she will assign values to the age composition variable,categorizing them by those who have at least 12% of residents who are over 64,those who have at least 35% of residents who are under 15,and those who have neither a high number of young or old residents.In assigning these values,Sarah is choosing

A) measurements.
B) conceptualizations.
C) indicators.
D) dimensions.