Final answer:
The FDIC's reserve fund comes from insured banks paying a premium on the money they insure.
Step-by-step explanation:
The FDIC's reserve fund comes from insured banks paying a premium on the money they insure. The insurance premium is based on the bank's level of deposits and adjusted according to the riskiness of the bank's financial situation. This insurance premium is the main source of funding for the FDIC's reserve fund.