Answer:C. The non-fiction book chapter, which analyzes and compares ports and coastal cities over a period of fifty years to the present day
The heading topic is economic competition between port cities in the U.S.
The main topic sentence is the root causes for economic competition between port cities in the U.S.
As we analyze the given options, the most helpful resource would be the non-fiction book— a book written based on facts. As this resource explained, it has a chapter that analyzes and compares ports and coastal cities over a period of fifty years to the present day. So this is more on the "history" of the ports and coastal cities. It mentioned also an "analysis" wherein you could possibly find the root causes of economic competition over the mentioned years.
Explanation: Other options, why not?
A. The novel about a stevedore
A novel is always fiction. Although the character of Stevedore relates to ports as a laborer, it will not be a reliable source in identifying the root causes for economic competition between port cities in the U.S.
B. The memoir chapter, which describes the lives of people who live and work in the port cities
Although a memoir is somewhat associated with a "biography", it will also be limited because it's just a written point of view of one person. In the end, a memoir chapter can be an additional source but still not the main source identifying the root causes for economic competition between port cities in the U.S.
D. The newspaper article, which reports recent events related to trade negotiations in your local port city
The newspapers can also be helpful since they might be containing related news or stories about the ports, but you need to gather at least all the newspapers for the past years. In the end, same as the memoir, the newspaper article can be an additional source but still not the main source identifying the root causes for economic competition between port cities in the U.S.
