Advo Company is purchasing carrying cases at a delivered cost of $8 per unit. The company, currently operating below full capacity. The costs to produce carrying cases is expected to be: Direct materials 3.00 Direct labor 4.00 Variable factory overhead (20% of direct labor) .60 Total variable cost per unit 7.60 If Advo Company makes the carrying cases instead, fixed factory overhead costs of $1.00 will not increase. The selling price of the carrying case will remain the same at $10. Advo Company should continue to purchase the cases because differential income is $.60 switch to making the cases because differential income is $ .60 switch to making the cases because differential income is $ .40 continue to purchase the cases because differential income is $ .40