Please state which function of money is being used by each of the following activities. Please explain the reasoning behind each answer.
(a) Brenda uses her last $20 bill to buy lunch.
(b) Brenda buys a $1,000 Savings Bond.
(c) Brenda puts her house on the market and sets an asking price at $300,000.
(d) Brenda deposits $400 into her banking account.