The mix between debt and owners fund is known as:

Option 1 -> Financial Decision refers to the overall process of making financing choices, but not specifically the mix itself.

Option 2 -> Working capital is the difference between current assets and current liabilities used for daily operations, unrelated to debt-equity mix.

Option 3 -> Fixed capital refers to long-term investment in fixed assets like machinery and buildings, not the financing mix.

Option 4 -> Capital structure specifically represents the proportion or mix of debt and owners' equity used to finance a company's assets and operations.

Hence, Option 4: Capital structure -> Capital structure is the specific term used in finance to describe the combination or mix of debt (borrowed funds) and owners' fund (equity) that a company uses to finance its overall operations and growth. It determines how a firm finances its assets through the combination of these two sources -> correct