How will the following events affect the demand for money? In each case, specify whether there is a shift of the demand curve or a movement along the demand curve and its direction.

a. There is a fall in the interest rate from 12% to 10%.

b. Thanksgiving arrives and, with it, the beginning of the holiday shopping season.

c. Increasingly, merchants are adopting electronic payment systems that allow more consumers to use PayPal and Apple Pay to make purchases.

d. The Fed engages in an open-market purchase of U.S. Treasury bills.