The Maxwell Corporation has a standard costing system in which variable manufacturing overhead is assigned to production on the basis of standard machine-hours. The following data are available for July:

• Actual variable manufacturing overhead cost incurred: $23,280

• Actual machine-hours worked: 1,900 hours

• Variable overhead rate variance: $3,870 Unfavorable

• Total variable overhead spending variance: $5,280 Unfavorable

The variable overhead efficiency variance for July is:

A. $9,150 Unfavorable

B. $1,410 Unfavorable

C. $1,410 Favorable

D. $9,150 Favorable