Which of the following statements is correct with regard to direct material variances and/or direct labor variances? O A. The direct labor efficiency variance can first be calculated at the point of production. OB. The production manager is held responsible for all direct labor variances. O C. The quantity purchased is used to determine the direct materials price variance. O D. The standard input ratio for direct materials represents the expected amount of direct material used to produce one unit of output. O E. All of the above statements are correct