Which of the Following Mathematical Expressions Is Found in a Typical

Which of the following mathematical expressions is found in a typical flexible-budget formula for overhead?

A) Total activity units + budgeted fixed overhead cost per unit.
B) Total activity units + actual fixed overhead cost per unit.
C) Budgeted variable overhead cost per unit + budgeted fixed overhead cost.
D) (Budgeted variable overhead cost per unit x total activity units) + budgeted fixed overhead costs.
E) (Budgeted fixed overhead cost per unit x total activity units) + (budgeted variable overhead cost per unit x total activity units) .