Table 5-1. Steel Shelf Company Category Cost Payment Period Cost Rent Monthly $3,000 Utilities Monthly 1,100 Insurance Quarterly 1,200 Property Taxes Annually 6,000 Steel Per Shelf 9.00 Forming Per Shelf 0.25 Labor Per Shelf 0.75 Price Per Shelf 20.00 Refer to Table 5-1. At 600 units of production, the Steel Shelf Company has total variable costs of a. $1,000. Ob. $12,000. c. $6,000. d. $5,000