Final answer:
Franklin Roosevelt's first inaugural address is the best primary source for an analysis of the Great Depression because it is a firsthand account from a key figure during that period. Grover Cleveland's address is not relevant to the era, and the other options are considered secondary sources.
Step-by-step explanation:
The best primary source to include in an analysis of the Great Depression would be d. Franklin Roosevelt's first inaugural address. A primary source provides direct or firsthand evidence about an event, and Roosevelt's first inaugural address, given during the Great Depression, offers insight into the government's response and the contemporary perspective of a leader at that time. In contrast, Grover Cleveland's first inaugural address predates the Great Depression, and the books by Amity Schlaes and David M. Kennedy are secondary sources, which interpret and analyze primary sources.
Economic, political, social, and cultural choices made in the 1920s, such as the stock market speculation, inadequate banking regulations, and uneven wealth distribution, were major contributing factors that led to the onset of the Great Depression.