A. It is the company's spontaneous liabilities-to-sales ratio that affects its need for external financing. A company with a higher spontaneous liabilities-to-sales ratio will have less need for external financing, because it can finance more of its working capital needs by using increases in accounts payable and accrued liabilities.

B. A company's profit margin is a factor that affects the company's need for external financing. The higher the company's profit margin is, the more net income will be available to fund increases in assets, and the less need the company will have for external financing.

C. A company's retention ratio is a factor that affects the company's need for external financing. The retention ratio is how much of the company's net income it does not pay out in dividends and thus retains in the company. The retention ratio is calculated as (net income - dividends paid) ÷ net income. Companies that pay out less of their net income in dividends have a higher retention ratio. The higher the retention ratio, the less need the company will have for external financing. Companies with smaller retention ratios will have a greater need for additional funds.

D. Rapid sales growth is a factor that affects a company's need for external financing. Rapid sales growth requires increases in assets, and increases in assets generate the need for external financing. The higher the growth rate in sales, the greater will be the need for additional financing.