Help inc. manufactures phones in a two-department process that involve assembly and finishing. the assembly department reported the follow data for the past month:

direct materials added $336,000

direct labor 460,800

factory overhead 230,400

total costs to account for $1,027,200

units started 80,000

units completed and transferred 67,200

units not complete 12,800

units in beginning inventory 0

The partially complete units at the end of the month were 100 percent complete with respect to materials and 75 percent complete with respect to conversion costs. The cost of a finished unit is ______. Show your work

a) $12.84

b) $13.20

c) $15.29

d) $17.20