Answer:
B. between 18 and 24
Step-by-step explanation:
The group with the least percent of population is the group with the smallest segment of the population. Out of the five age groups stated in the table above, those who are aged between 18 and 24 constitute the least percentage of 9.9%, making up the smallest segment of the population in 2010 with a population of 30,672,088 people. This is the least of all the age groups listed.
Therefore, the answer is "B. between 18 and 24."