Loop 1604 Inc. has prepared a static budget at the beginning of the month. At the end of the month the following information is available:

Static Budget:

Sales volume: 1,000 units: Price $70 per unit

Variable costs: $32 per unit: Fixed costs: $37,500 per month

Operating Income: $500

Actual Results:

Sales volume: 990 units: Price $74 per unit

Variable costs: $35 per unit: Fixed costs: $33,000 per month

Operating Income: $5,610

Calculate the flexible budget variance for Sales Revenue.

$3,960 U

$5,490 U

$3,960 F

$5,490 F