Which of the following best describes FDR's "fireside chats"?

FDR's "fireside chats" were weekly radio broadcasts that aimed to directly engage and reassure the American public during challenging times, especially during the Great Depression and World War II. These informal, conversational broadcasts allowed Franklin D. Roosevelt to communicate his policies, explain government initiatives, and foster a sense of connection and trust with citizens. The relaxed format of these chats made it feel as if the President was speaking directly to individual families in their homes, which was a novel approach at the time and contributed significantly to Roosevelt's popularity.

Other options do not capture the essence of these chats; they were not formal addresses to Congress, public speeches at rallies, or letters sent to citizens. Instead, they utilized the emerging medium of radio to establish a more personal rapport with the American people, demonstrating Roosevelt's understanding of the power of communication in shaping public sentiment.