What type of financing involves a fixed interest paid over a specific period followed by the repayment of the full amount?

The correct answer is debentures. Debentures represent a type of debt instrument that companies use to borrow money at a fixed interest rate. Investors lend money to the issuer of the debenture, and in return, they receive periodic interest payments over the life of the debenture. At the end of the specified period, known as the maturity date, the issuer repays the principal amount borrowed. This arrangement provides both the issuer and the investor with a clear timeline for repayment and predictable interest earnings.

In contrast, shares represent ownership in a company and do not involve fixed interest payments or a guaranteed return of capital. Bank loans typically have their own terms but can vary widely in structure, and they may not always adhere to the fixed interest and repayment characteristics of debentures. Grants are funds provided by governments or organizations that do not require repayment, as they are given for specific purposes, often without expectation of financial return. Thus, the defining features of debentures align perfectly with the question's criteria.