Hello, I need help in this question

For each of the following scenarios, indicate how the economy-wide demand for U.S. money would change, what would happen to the nominal interest rate if the Fed doesnotchange the money supply. Then illustrate, using the supply and demand for money, what the Fed would need to do in order to keep interest rate at existing levels.

a) Online trading websites and apps decrease the cost of buying and selling stocks and bonds.

b) The popularization of credit card readers makes it so that virtually all vendors accept cash.

c) Newspapers start to publish articles about local residents who made a fortune by trading cryptocurrencies.