The following is monthly budgeted cost and activity information for two activities in the purchasing department of X Company: Cost Driver Activity Supplier relations Invoicing Variable Costs $10,260 $11,550 Fixed Costs $16,900 $24,400 380 suppliers 770 invoices In November, actual costs and activity were as follows: Activity Supplier relations Invoicing Total Costs $28,151 $36,706 Driver Amount 440 suppliers 763 invoices What was the flexible budget variance for the supplier relations activity for November (assume that favorable variances are positive numbers and unfavorable variances are negative numbers)? OA: $-17,891| OB: $-16,271 OC: $-11,251 OD: $-991 E: $0 F: $629