Answer:
I'm assuming you're doing research for a paper or something. It's asking why you chose the sources you chose.
Step-by-step explanation:
Pick a source and think about why it is helpful to you. Does it contain a statistic that supports your point of view? Does it contain some sort of evidence or reasoning that supports your point of view? It looks like the boxes are pretty big so try to elaborate as much as you can. I hope this is what you were looking for.