Answer:
C. real interest rates rise and investment spending falls
Step-by-step explanation:
Due to the decrease in the money supply, keeping other things remain constant. The investment spending falls and due to the shortage of money, the real interest rate is rise so that it will become expensive for the customer to take out the loan.
Hence, it shows a direct relationship between the change in money supply and the investment spending while in respect of real interest rate it shows an inverse relationship between the change in money supply and real interest rate.
Hence, all other options are wrong except C.