A list of contact persons is most likely to be required for which of the following?

A list of contact persons is especially relevant for longitudinal studies, where researchers follow the same individuals over a period of time to gather data at multiple points. In this scenario, where college students are being tracked from their freshman to senior year, having a list of contact persons enables researchers to maintain communication with the participants and ensure they can be reached for surveys or assessments during each phase of the study.

In longitudinal studies, participants may change addresses, phone numbers, or emails over the years, thus having updated contact information is crucial for the effectiveness of the research. This allows the researchers to minimize attrition rates and maintain a robust sample size throughout the duration of the study.

While other options may involve gathering contact information at the outset, such as one-time events or specific studies, the requirement for continuous tracking in option B distinctly underscores the necessity of a contact list to facilitate ongoing engagement and data collection over time.