Lei's investment manager told her that if she wants to increase the return on the money currently in her checking account, she should invest in a bank certificate of deposit. This is

a short-term (one-year) IOU issued by the bank.

a long-term IOU issued by governments and corporations.

a unit of ownership in a corporation.

a short-term obligation of the U.S. Treasury with a maturity period of one year or less.

a bond issued by a state or local government or agency.