The following standards for variable manufacturing overhead have been established for a company that makes only one product:

Standard hours per unit of output ----------- 2.7 hours

Standard variable overhead rate ------------ $13.05

The following data pertain to operations for the last month:

Actual hours ------------------------------------------------ 2,400 hours

Actual total variable manufacturing overhead cost --- $30,360

Actual output ----------------------------------------------- 600 units

What is the variable overhead efficiency variance for the month?

	a.	$9,219 U
	b.	$10,179 U
	c.	$9,867 U
	d.	$648 U