Answer:
The most useful way to research this information would be by investigating primary sources.
Explanation:
A source is the place of origin of something and there are many types, especially in the research ambit. A primary source is the original source, such as a <em>document, </em>or <em>direct testimonies</em> from people, for example.
In this case, Angelica's best way of learning how many pedestrians walk by a specific location is to <em>go there </em>and be able to see for herself and ask for <em>testimonies from individuals who frequent that specific location. </em>
