Assume the following: The variable portion of the predetermined overhead rate is $3.50 per direct labor hour.

The standard labor hours allowed per unit of finished goods is 3 hours.

The actual quantity of labor hours worked during the period was 44,000 hours.

The total actual variable manufacturing overhead cost for the period was $63,000.

The company produced 15,000 units of finished goods during the period.

What is the variable overhead efficiency variance?

a) $3,500F

b) $3,431U

c) $3,431F

d) $3,500U