Question

Why is it important to select a topic that has a broad scope

Answer 1

 to be able to gather information from a variety of sources. Because if you have a broad topic, there is so much that you can research and so many sources you can use. That is why I believe this is the correct answer. 

Answer 2

You can go a lot easier on yourself by selecting a topic with a broad scope. When you do this, you have access to more resources and more perspectives than you would with a smaller scope topic. You can gather information from numerous sources, which helps you ensure that the facts you're presenting are accurate.
I hope this helps you <3