The detail that best shows the connection between feedback and performance is Option D, as it directly links increased concentration and improved outcomes to receiving engagement level feedback.
The correct answer that shows the connection the author makes between feedback and performance is:
D: “Subjects who were shown their engagement level while performing a task were able to learn to control their concentration and outperformed control groups while reporting a lower perceived workload.” (Paragraph 5)
This detail directly illustrates how feedback on engagement levels can help improve an individual's performance, as it demonstrates an enhanced ability to maintain concentration when feedback is given. Furthermore, this suggests a direct correlation between regular performance feedback and increased efficiency, as the subjects not only did better but also felt the tasks were less strenuous.