Step 1: Distinguish between dividend and interest.
Dividend is a distribution of a portion of a company's earnings, decided by the Board of Directors, to a class of its shareholders. It is not an obligation and depends on the company's profitability and policy.
Interest is the cost of borrowing money. It is a charge against profit and a legal obligation that must be paid to lenders (like bondholders or banks) regardless of whether the company makes a profit.
Step 2: Identify the obligatory payment.
The payment that is a mandatory obligation is interest on debt.