The following is Porte Alegre Co.'s contribution format income statement for last month: Sales Variable expenses Contribution Margin Fixed expenses Net Operating Income $800,000 $300,000 $500,000 $400,000 $100,000 The Company has no beginning or ending inventories. The company produced and sold 10,000 units last month. What is the company's break-even sales in dollars? $0 $640,000 O $700.000 $400.000