The Efficiency Variance Computed on a Three-Variance Approach Is

The efficiency variance computed on a three-variance approach is

A) equal to the efficiency variance computed on the four-variance approach.
B) equal to the variable overhead spending variance plus the efficiency variance computed on the four-variance approach.
C) computed as the difference between applied variable overhead and actual variable overhead.
D) computed as actual variable overhead minus the flexible budget for variable overhead based on actual hours workeD.