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

Standard hours per unit of output	7.0	hours
Standard variable overhead rate	$13.40	per hour

The following data pertain to operations for the last month:

Actual hours	2,725	hours
Actual total variable manufacturing overhead cost	$37,195
Actual output	150	units

What is the variable overhead efficiency variance for the month?

$680 F

$23,125 U

$22,445 U

$14,070 F