5. A good approximation of the long-term "risk free (interest) rate" is the yield/rate on a A good approximation of the short-term "risk free (interest) rate" is the yield rate on a A. Federal Funds Rate... Discount Rate B. 10-Year U.S. Treasury Bond...90-Day U.S. Treasury Bill C. 30-Year U.S. Treasury Bond...30-Day U.S. Treasury Bill D. Prime Rate Bank Loan (interest rate banks charge their best/prime borrowers), for both