The standard factory overhead rate is $10 per direct labor hour ($8 for variable factory overhead and $2 for fixed factory overhead) based on 100% capacity of 30,000 direct labor hours. The standard cost and the actual cost of factory overhead for the production of 5,000 units during May were as follows: Standard: 25,000 hours at $10 $250,000 Actual: Variable factory overhead $197,500 Fixed factory overhead 60,000 What is the amount of the factory overhead controllable variance? a) -$10,000 Favorable b) $10,000 Unfavorable c) -$2,500 Favorable d) $2,500 Unfavorable