During the last fiscal year, MLX Inc had revenues and expenses of $250,000 and $150,000 respectively on sales of 10,000 units. The company had net operating assets of $200,000. The company's required rate of return for approval of projects is 20%. MLX's total fixed costs were $50,000. The company's expenses included $30,000 of selling, general and administrative expenses, $10,000 of were variable. Calculate the company's mark-up percentage on total variable cost if the company expects to sell 18,000 units during the next fiscal year.

a)20%

b)40%

c)50%

d)60%