Answer
Step1: Secured and unsecured bonds
Step2: Convertible and callable
Work Step by Step
Step1: Secured bonds have specific assets pledged as collateral security of the issuer. Unsecured bonds are issued against general security and credit of the issuer.
Step2: Convertible bonds are the bonds which can be converted into common stock at the bondholder's option. Callable bonds can be retired by the issuing company at a stated dollar amount.