What type of risk is the fundamental risk factor for fixed-income securities?

Comprehensive and Detailed Explanation From Exact Extract:

Interest rate risk is the primary risk for fixed-income securities, as their value decreases when interest rates rise due to fixed cash flows. The feedback from the document states:

"Interest rate risk is the fundamental risk factor for fixed-income securities such as bonds, mortgages and preferred shares. As interest rates move up, the value of a fixed-income security falls. This is because the cash flow from the fixed-income security is fixed."