Final answer:
Maria is concerned about the net working capital ratio. This ratio measures a company's ability to meet its short-term financial obligations.
Step-by-step explanation:
Maria is concerned about the net working capital ratio. The net working capital ratio measures a company's ability to meet its short-term financial obligations. It is calculated by subtracting current liabilities from current assets. If the net working capital ratio is low, it suggests that the company may have difficulty paying off its loans and clearing its current accounts receivables.