Harrison et al. are conducting a study assessing the ability of depressed versus non-depressed participants to remember negative emotions in a short story about a family whose car breaks down. They plan to ask participants to read the story and then make a list of the emotions expressed in the story. Before beginning the study, they make a list of negative emotions (e. g., sadness and anger) that they will record from the participants’ responses. In this example, negative emotions are the .

a. dependent variable
b. independent variable
c. operational definition
d. significant variable