overhead data:

Budgeted output units

Budgeted fleet hours

Budgeted variable manufacturing overhead costs for $680$ loads

Actual output units produced and delivered

Actual fleet hours

$680$ truckloads

$476$ hours

$$72,590$

$615$ truckloads

$376$ hours

$$67,790$

Actual variable manufacturing overhead costs

$$67,790$

What is the flexible$-$budget variance for variable manufacturing overhead?

A$.$ $$4,800$ favorable

B$.$ $$4,800$ unfavorable

C$.$ $$2,139$ favorable

D$.$ $$2,139$ unfavorable