Answer:
The correct answer is D: $13
Step-by-step explanation:
Giving the following information:
Cost per Unit Cost per Period:
 Direct materials $ 6.20 
Direct labor $ 2.80 
Variable manufacturing overhead $ 1.45 
Fixed manufacturing overhead $ 12,000 
Sales commissions $ 1.00 
Variable administrative expense $ 0.55 
Fixed selling and administrative expense $ 4,000
Price= 25
Contribution margin= Price - variable costs
Variable costs= direct materials + direct labor + variable manufacturing overhead + sales commissions + variable administrative expense
Variavle costs= 6.20 + 2.80 + 1.45 + 1 + 0.55= $12
Contribution margin per unit= 25 - 12= $13