Pick the odd one out from the following:

Secured debentures Bearer debentures Preference debentures Redeemable debentures

Preference debentures

The other three options, i.e., Secured debentures, Bearer debentures, and Redeemable debentures, all describe specific characteristics or features of debentures, such as whether they are secured by company assets, the form of ownership, or their redemption terms. In contrast, "Preference debentures" is not a standard term in the context of debentures, and it doesn't describe a common type of debenture.