Answer: Either a financing or an operating cash flow.

Under International Financial Reporting Standards (IFRS), companies have the flexibility to classify interest expense as either an operating activity or a financing activity. This contrasts with US GAAP, which mandates that interest expense be classified as an operating activity, while the principal amount of debt is treated as a financing activity. Therefore, the correct answer is **C**, as IFRS allows for either classification.

Author: LeetQuiz Editorial Team