The "First Hundred Days" refers to the initial period of approximately the first three months of Franklin D. Roosevelt's presidency, starting from his inauguration on March 4, 1933. During this time, FDR implemented a series of ambitious and wide-ranging measures aimed at addressing the economic crisis of the Great Depression.
This period is notable for a rapid and significant amount of legislation aimed at economic recovery, and it set a precedent for future presidents regarding the legislative agenda during the early days of their administration. Some of the key programs introduced during this time included the Emergency Banking Act, the Civilian Conservation Corps (CCC), and the Agricultural Adjustment Act (AAA), among others, which formed the foundation of his New Deal policies.
Thus, the correct answer is "approximately the first three months of FDR's presidency."