The Static Budget,at the Beginning of the Month,for Bob's Deep

The static budget,at the beginning of the month,for Bob's Deep Sea Fishing Company follows: Static budget:
Sales volume: 2,000 units; Sales price: $50.00 per unit
Variable costs: $13.00 per unit; Fixed costs: $25,200 per month
Operating income: $48,800
Actual results,at the end of the month,follows:
Actual results:
Sales volume: 1,900 units; Sales price: $58.50 per unit
Variable costs: $16.5 per unit; Fixed costs: $33,400 per month
Operating income: $46,400
Calculate the flexible budget variance for operating income.

A) $3,700 U
B) $3,700 F
C) $1,300 F
D) $16,150 F