Which demographic groups were compared in the studies?

• A. High school students 14-18 and adults 30-50
• B. Retirees and students 65+
• C. Children 6-12 and teens 13-17
• D. University students ages 18-31 and online-recruited adults ages 18-60

Answer: (D)

This item is about how studies choose and contrast participant groups. The best option names two distinct adult populations that researchers often compare: university students and a broader online-recruited adult sample, with overlapping ages to keep the comparison meaningful and broad enough to examine generalizability. By using ages 18–31 for students and 18–60 for online-recruited adults, the design clearly contrasts a specific, educationally-oriented group with a more diverse adult group, which helps researchers see how findings might generalize beyond one setting.

The other pairings involve groups that are less typical for direct adult-based comparisons or include minors or clearly separate life stages, which would complicate interpretation or align with different research questions.