Final answer:
FDR's 'Brain Trust' was a group of advisors who helped craft varied relief and recovery programs, showing his commitment to bold experimentation to address the Great Depression.
Step-by-step explanation:
Franklin D. Roosevelt's "Brain Trust" illustrated his policy of bold experimentation during a time of national crisis by providing a diverse pool of ideas and solutions to combat the Great Depression. This advisory group, consisting of experts like Rexford Tugwell, Raymond Moley, and Adolph Berle, played an essential role in formulating programs that spanned from new tax policies to agricultural reform.
Their collective efforts resulted in significant legislative proposals such as the National Recovery Administration (NRA) and the foundation for Social Security, demonstrating a pragmatic approach to governance and willingness to try a multitude of strategies, underlining Roosevelt's commitment to steering the nation toward recovery.