Final answer:
The Federal Deposit Insurance Corporation (FDIC) provides deposit insurance to prevent bank runs, making it the best example of a reform put in place to prevent another Great Depression. Therefore, the correct option is A.
Step-by-step explanation:
The BEST example of how reforms were put into place to prevent another Great Depression is a:
a. The Federal Deposit Insurance Corporation provides deposit insurance to prevent bank runs
The FDIC was created in 1933 as part of President Franklin D. Roosevelt's New Deal reforms. It guarantees individual bank deposits, providing confidence to depositors and preventing bank runs. This measure was aimed at stabilizing the banking system and preventing a repeat of the financial crisis that led to the Great Depression.