In a subsequent 4 week period, Birch Co’s actual fixed costs were $3,500. There were 18,000 units produced. The budgeted fixed costs was $3,000 based on budgeted production of 17,500 units. Calculate the fixed production overhead total variance. A. $440 (A) B. $525 (A) C. $500 (F) D. $500 (A) Sir answer is A. Why the Fixed cost has been treated as Variable cost here?