A manufacturing company that produces a single product has provided the following data concerning its most recent month of operations:

Units in beginning inventory 0
Units produced 8,900
Units sold 8,500
Units in ending inventory 400
Variable costs per unit:
Direct materials $ 26
Direct labor $ 25
Variable manufacturing overhead $ 4
Variable selling and administrative expense $ 4
Fixed costs:
Fixed manufacturing overhead $ 249,200
Fixed selling and administrative expense $ 17,000

What is the variable costing unit product cost for the month?

a. $59 per unit

b. $55 per unit

c. $87 per unit