Which of the following statements is correct concerning standard costing and/or variance calculations? A. A favorable quantity (efficiency) variance indicates that a company used less input than expected for the actual level of output. B. Variances falling outside of an acceptable range of outcomes require investigation. C. A price (rate) variance calculates the difference between what a company paid and what it expected to pay for its production input. D. Standards are used at the beginning of the period to budget and at the end of the period to evaluate performance. E. All of the above statements are correct