The Federal Funds Rate Refers to the

The federal funds rate refers to the

A) percentage of federal spending that is made up of "uncontrollables," budget items that cannot be controlled through the regular budget process.
B) percentage of federal spending on programs that are controlled through the regular budget process.
C) congressionally determined limit on the amount of national debt that can be issued by the U.S.Treasury.
D) interest rate on loans between banks.