Righway Corporation has supplied the following data: Sales per period. 1,000 units Selling price $50 per unit Variable manufacturing cost $20 per unit Selling expenses.... $10,000 plus 5% of sales Administration expenses. $5,000 plus 15% of sales The total contribution margin per period is: A. $22,500 B. $27,500 C. $30,000 D. $20,000 The break-even point per period is (round to nearest unit): A. 750 units B. 545 units C. 500 units D. 667 units If the selling price is changed to $55 per unit, the break-even point will be (round to nearest unit): A. 667 units B. 545 units C. 625 units D. 500 units