The Static Budget,at the Beginning of the Month,for La Verne

The static budget,at the beginning of the month,for La Verne Company follows: Static budget:
Sales volume: 2100 units: Sales price: $56.00 per unit
Variable cost: $14.00 per unit: Fixed costs: $26,000 per month
Operating income: $62,200
Actual results,at the end of the month,follows:
Actual results:
Sales volume: 1800 units: Sales price: $59.00 per unit
Variable cost: $16.00 per unit: Fixed costs $35,000 per month
Operating income: $42,400
Calculate the sales volume variance for variable costs.

A) $12,600 U
B) $4200 F
C) $300 U
D) $12,600 F