Russo Corporation manufactured 21,000 air conditioners during November. The overhead cost-allocation base is $34.50 per machine-hour. The following variable overhead data pertain to November: Actual 21,000 units 12,700 hours 534.00 Budgeted Production Machine-hours Variable overhead cost per machine-hour What is the total variable overhead variance? 23,000 units 13,800 hours 34.50 O A. $3,450.00 favorable O B. $3,450.00 unfavorable OC. $2,900.00 favorable OD. $2,900.00 unfavorable