Stroth Corporation uses activity-based costing to compute product margins. Overhead costs have already been allocated to the company's three activity cost pools-Machining, Order Filling, and Other. The overhead costs of $5,292 Machining and $1,250 Order Filling were allocated to Product C4. Sales and direct cost data are combined with Machining and Order Filling costs to determine product margins as shown below: Sales (total) Direct materials (total)...... Direct labor (total) Product C4 $46,900 $15, 100 $22,300 Product L4 $25,300 $11,500 $10,900 What is the product margin for Product C4 under activity-based costing? A. $-1,000 B. $2,958 C. $9,500 D. $4,208