Answer:
The correct answer is A.
Step-by-step explanation:
Giving the following information:
Direct materials= $7.35 
Direct labor= $3.55 
Variable manufacturing overhead= $1.40 
Sales commissions= $1.15
Variable administrative expense= $0.70 
The selling price is $27.80
The contribution margin is the result of deducting from the selling price all the variable cost components. 
Contribution margin= selling price - (direct material + direct labor + variable overhead + sales comission + variable administrative expense)
Contribution margin= 27.8 - 14.15= $13.65