Answer:
The answer is D.
Explanation:
Note Bearer-form bond is a type of bond that is paid to the person presenting the the cheque at that very moment unlike registered-form bond is paid ONLY to the person that his name has been registered with the security exchange for the bond. Even if a stranger picks it up somewhere or is being stolen, the bond will not be honoured.
Option A(debenture) is incorrect because debenture is an unsecured long-term loan.
Option B(Callable bond) is also incorrect. This is a bond that can be claimed or redeemed by the person issuing it before its maturity.