Final answer:
Preferred stock is not a money market instrument, while Treasury bills, bankers' acceptances, and commercial paper are examples of money market instruments.
Step-by-step explanation:
The correct answer is d. preferred stock.
Money market instruments are short-term debt securities with high liquidity and low risk. They are typically issued by governments, financial institutions, and corporations to raise funds on a short-term basis. Treasury bills, bankers' acceptances, and commercial paper are all examples of money market instruments. However, preferred stock is not considered a money market instrument. Preferred stock is a type of equity security that represents ownership in a company and pays dividends, but it is not a short-term debt security.