Questions 8-10 are based on the following revenue and cost structure: Selling price per unit: Variable cost per unit: S 100 S 40 $12,000 40% Total fixed costs: ax rate on operating income: CPA Adapted] Theta Company sells product A at a selling price of S40 per unit. Theta's cost per unit based on the full capacity of 500,000 units is as follows: S 6 Direct materials Direct labour Indirect manufacturing (60% of which is fixed) 10 S19 A one-time-only special order offering to buy 50,000 units was received from an overseas distributor. The only other costs that would be incurred on this order would be S4 per unit for shipping. Theta has sufficient existing capacity to manufacture the additional units. In negotiating a price for the special order, Theta should consider that the minimum selling price per unit should be a. $17. b.S1 c. $21 d. $23