Corp has a bond issue in which the bonds pay back the principal in installments throughout the life of the bond.Additionally, the bonds can be converted into common stock at the bondholder's discretion at any point prior to maturity, and are debenture bonds.The bonds are correctly classified as which one?

Serial, commodity-backed, unsecured bonds

Serial, convertible, registered bonds

Serial, convertible, unsecured bonds

Serial, convertible, revenue bonds

Term, convertible, unsecured bonds