Answer:
C. panel data
Explanation:
Based on the information provided within the question it can be said that the data gathered from this study is an example of panel data. This term refers to data that is gathered from observing phenomenons over a period of time from the same groups or individuals. Which is exactly what the study did by observing the changes on teenage employment (singular group/category) over a period of 24 years from 1980 to 2004.