The management of Clean Energy Manufacturing is analyzing vanable overtead variances tor the fiscal period just ended. The flexible budget caled for $70,400 in variable overthead t actual varbabie overhead was 380,000 in computing the overhead variances, Clean's management discovered that it had used 32,000 pounds of direct material, father than the budgeted amount of 35,200 pounds. (Pounds of direct material is the single owertiead driver of variable overhead) The standard variable cverhead rate per pound of direct material is 52.00 What is Clean's variable overhead etficiency variance? a. $19,200 (U) b. 312,500 (F) c 56.400(5) d. 36.400 (U)