The static budget data, at the beginning of the month, for WXY 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 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 Calculate the flexible budget variance for operating income.

A.$3700 F B. $1300 U C. $3700 U D. $1300 F