The Management of Green Energy Manufacturing Is Analyzing Variable Overhead

The management of Green Energy Manufacturing is analyzing variable overhead variances for the fiscal period just ended. The flexible budget called for $176,000 in variable overhead but actual variable overhead was $100,000. In computing the overhead variances, Green's management discovered that it had used 40,000 pounds of direct material, rather than the budgeted amount of 44,000 pounds. (Pounds of direct material is the single overhead driver of variable overhead) . The standard variable overhead rate per pound of direct material is $2.00.
What is Green's variable overhead efficiency variance?

A) $16,000 (F)
B) $ 8,000 (F)
C) $24,000 (U)
D) $ 8,000 (U)