The variable overhead efficiency variance measures the difference between the ________, multiplied by the budgeted variable overhead cost per unit of the cost-allocation base.

	a.	actual cost incurred and the budgeted quantity of the cost-allocation base that should have been used to produce the actual output
	b.	budgeted cost and the actual cost used to produce the actual output
	c.	budgeted quantity of the cost-allocation base used and the budgeted quantity of the cost-allocation base that should have been used to produce the actual output
	d.	None of the answers.
	e.	actual quantity of the cost-allocation base used and the budgeted quantity of the cost-allocation base that should have been used to produce the actual output