Debentures which are transferable by mere delivery are:

Bearer debentures

The correct answer is option 3- Bearer debentures.

Debentures which are transferable by mere delivery are Bearer debentures.

Bearer debentures can be transferred simply by delivery, and the company does not maintain any records of the debenture holders. Interest payments on bearer debentures are made to whoever presents the attached interest coupon.

OTHER OPTIONS

• Registered Debentures: Registered debentures have detailed information about debenture holders, including their names, addresses, and holdings, recorded in a company-maintained register. These debentures can only be transferred through a formal transfer deed.

• Unsecured Debentures: Unsecured debentures do not have a specific claim on the company's assets. However, in the event of default, a floating charge may be created on these debentures. Generally, companies do not issue these types of debentures.