The standard factory overhead rate is $7.50 per machine hour ( $6.20 for variable factory overhead and $1.30 for fixed factory overhead) based on 100% of normal capacity of 80,000 machine hours. The standard cost and the actual cost of factory overhead for the production of 15,000 units during August were as follows: What is the amount of the variable factory overhead controllable variance? a. $12,000 unfavorable b. $26,000 unfavorable c. $12,000 favorable d. $14,000 unfavorable