Hi I need help with this question

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

Standard hours per unit of output8.0hoursStandard variable overhead rate$14.40per hour

The following data pertain to operations for the last month:

Actual hours2,850hoursActual total variable manufacturing overhead cost$41,770Actual output200units

What is the variable overhead efficiency variance for the month?

$18,730 U

$18,000 U

$730 F

$23,040 F