Lauren, a 14-year-old, was fond of writing short stories and wrote at least three stories every week. When her parents found out about this, they promised to give her some incentive if she wrote more than three stories per week. Initially, Lauren felt motivated and exceeded the count. However, after a few weeks, she lost interest and began to consider writing a chore. Which of the following psychological effects is illustrated in this scenario?
A. the spacing effect
B. the overjustification effect
C. the facial feedback effect
D. the halo effect