A researcher is curious about whether or not therapy animals relieve stress in humans. The researcher is a college professor, and he notices that his university is bringing therapy dogs to campus during finals week. Students who sign up for an “Anti-Stress Pet Visit” get to spend an hour petting and playing with the dogs. The professor receives permission to conduct a research study on the students who attend the events. Before students visit with the dogs, he asks them to complete a one-item stress scale: “How much stress are you currently experiencing? 1: No stress at all, 2: Moderate stress, 3: High stress.” After the students visit with the dogs, they complete the scale a second time. What is the sample used for this study?What is the population of interest to the researcher?Is the researcher gathering quantitative data or qualitative data?What is the independent variable?What is the dependent variable?