Which of the following is considered part of the U.S. money supply? (Use the M1 measures.)
a. A $$\$ 10$$ bill you carry in your wallet
b. A $$\$ 100$$ traveler's check you bought but did not use
c. A $$\$ 100$$ bill in a bank's vault
d. The $$\$ 325.43$$ balance in your checking account
e. A share of General Motors stock worth $$\$ 40$$