Question

scientists informed the volunteers they had a new target. each had to report the orientation of the line inside a blue diamond. again, groups of six symbols appeared on a computer screen. only one was a diamond. the other five were still circles. in some trials, one of those circles was red or green. in other trials, there were no red or green circles.
the recruits were told to answer as quickly as possible. and for this phase of the experiment, no additional money would be earned.
the researchers now measured how long it took people to find the diamond and record their answers.
when no red or green circles were among the onscreen options, both adults and teens responded quickly. but when a red or green circle showed up, both groups initially took a bit longer. adults, though, quickly stopped paying attention to the colored circles. their response times sped up.
teens reacted differently. they took longer to respond whenever a red or green circle showed up. their response times never sped up. their attention still was drawn to the previously valued circles - even though the shapes no longer brought any reward. clearly, the red and green circles were distracting teens from their objective.
guiding questions
what do the findings of ropers experiment suggest?
a both adults and teens are distracted by rewards, which affects their response speed.
b teens are less easily distracted by rewards than adults, which helped them to do better to the task.
c teens are more easily distracted, even when they dont gain a reward.
d teens reacted differently to the task because they were not able to remember their previous training.

Explanation:

The text describes an experiment. When there were no colored (red or green) circles (no reward - related distraction as per context), both adults and teens were quick. When colored circles (previously associated with reward) appeared, adults' response times initially longer but then sped up (they stopped being distracted). Teens, however, took longer to respond when colored circles (no reward now) showed up and their response times never sped up. Their attention was still drawn to the previously - rewarded (colored) circles even when there was no reward. So, teens are more easily distracted (by previously - rewarded stimuli even when no reward) compared to adults.

Answer:

C. Teens are more easily distracted, even when they don't gain a reward.