The Static Budget,at the Beginning of the Month,for Helloise Décor

The static budget,at the beginning of the month,for Helloise Décor Company follows: Static budget:
Sales volume: 2,100 units: Sales price: $58.00 per unit
Variable cost: $14.00 per unit: Fixed costs: $27,000 per month
Operating income: $65,400
Actual results,at the end of the month,follows:
Actual results:
Sales volume: 1,850 units: Sales price: $59.00 per unit
Variable cost: $18.00 per unit: Fixed costs $35,000 per month
Operating income: $40,850
Calculate the sales volume variance for variable costs.

A) $11,000 U
B) $3,500 F
C) $250 U
D) $11,000 F