The following costs relate to Southern Company: Variable manufacturing cost, $30; variable selling and administrative cost, $8; applied fixed manufacturing overhead, $15; and allocated fixed selling and administrative cost, $4. If Southern uses total-cost pricing formulas, the company's markup percentage would be computed on the basis of:

Select one: a. $45. b. $57. c. $38. d. none of the other answers are correct. e. $30.