At a sales volume of 44,000 units, Thoma Corporation's sales commissions (a cost that is variable with respect to sales volume) total $585,200. To the nearest whole cent, what should be the average sales commission per unit at a sales volume of 46,300 units? (Assume that this sales volume is within the relevant range.) A. $13.99 B. $13.30 C. $12.99 D. $12.67