The four tools of monetary policy in a limited reserve environment, as presented in Chapter 16 of your text: a) are open market operations, the reserve ratio (R), the discount rate, and tax changes. b) are open market operations, the reserve ratio (R), the discount rate, and changes in government spending. c) haven't changed in over 50 years. d) are open market operations, the reserve ratio (R), the discount rate, and interest on reserve balances (IORB).