Pyrdum Corporation produces metal telephone poles. In the most recent month, the company budgeted production of 3,500 poles. Actual production was 3,800 poles. According to standards, each pole requires 4.6 machine-hours. The actual machine-hours for the month were 17,800 machine-hours. The standard variable manufacturing overhead rate is $5.40 per machine-hour. The actual variable manufacturing overhead cost for the month was $96,712. The variable overhead efficiency variance is: A) $2,320 U B) $1,728 F C) $2,320 F D) $1,728 U