Batdorf Corporation's relevant range of activity is 2,000 units to 6,000 units. When it produces and sells 4,000 units, its average costs per unit are as follows: Cost per Unit Direct materials $7.15 $3.40 $1.35 $2.80 Direct labor Variable manufacturing overhead Fixed manufacturing overhead Fixed selling expense Fixed administrative e pense Sales commissions Variable administrative expense $0.70 $0.40 $0.50 $0.40 If 5,000 units are produced in September, what is the unit cost of these units for external financial reporting purposes? O $14.13 O $14.70 O $15.23 O $16.70 None of the above