Which bond mutual funds has both the lowest default risk and interest rate risk?

Bond mutual funds that primarily invest in Treasury securities, such as Treasury bond funds, typically exhibit both the lowest default risk and interest rate risk. Treasury bonds are backed by the U.S. government, ensuring minimal default risk. Additionally, funds with shorter durations tend to have lower interest rate risk, as they are less sensitive to changes in interest rates. Thus, a short-term U.S. Treasury bond fund would generally be a suitable choice for minimizing both risks.