What determines the supply curve for reserves? (Check all that apply) The supply of reserves is determined by A. borrowed reserves in the form of discount loans from the Fed. B. the Fed's manipulation of reserve requirements. C. borrowed reserves in the form of regular loans. D. the Fed's provision of non-borrowed reserves through open market operations. Why does the supply curve have a horizontal segment? A. Because the interest rate that the Fed pays on reserves sets a ceiling on the federal funds rate. B. Because the discount rate sets a ceiling on the federal funds rate. C. Because the interest rate that the Fed pays on excess reserves sets a ceiling on the discount rate. D. Because the federal funds rate sets a ceiling on the discount rate