Harding Air uses two measures of activity, fights and passengers, in the cost formulas in its budgets and and actual activity in August in terms of the number of flights and passengers are listed below. The actual co plane operating costs in August was $255,690. Budgeted cost formula: Plane operating cost (fixed cost) Flight cost Passenger cost $ 39,590 per month $ 2,649 per flight $ 12 per passenger August budget Actual 80 flights 85 flights 286 passengers 301 passengers 13 The activity variance for plane operating costs in August would be closest to: A. $ 26,165 Unfavorable B. $ 13,065 Unfavorable C. $ 13,425 Unfavorable D. S 13,245 Unfavorable E. None of the above