Franklin, inc is investigating the possibility of adding a new skateboard to its lineup of products. The marketing department believes that 10,000 units can be sold at $90 each. Franklin requires a 25% profit margin(i.e cost is 75% of the selling price) on all products. To achieve its goal, Franklin must keep per unit cost equal to or less than.

a. $22.50 b. $50.63 c. $67.50 d. $90.00