Explanation:

Mezzanine debt is the correct answer because it typically includes equity participation features. Here's why:

1. Mezzanine Debt Characteristics:

   • Mezzanine debt is a hybrid financing instrument that combines debt and equity features
   • It often includes equity warrants or conversion rights that allow lenders to participate in the company's equity upside
   • This equity participation compensates lenders for taking higher risk than senior debt holders

2. Comparison with Other Options:

   • Distressed Debt: While distressed debt investors may sometimes gain equity through debt-for-equity swaps in restructuring situations, this is not a standard feature of the investment category itself
   • Unitranche Debt: This is a single loan that combines senior and subordinated debt features, but typically doesn't include equity participation options

3. Investment Rationale:

   • Mezzanine lenders accept lower current interest rates in exchange for potential equity upside
   • The equity kicker (warrants or conversion rights) provides additional return potential if the company performs well
   • This structure aligns the interests of lenders and equity holders

Key Takeaway: Mezzanine debt is specifically structured to provide lenders with equity participation options as compensation for taking subordinated debt positions with higher risk profiles.