Which of the following statements are true? a. When the materials price variance is recorded at the time of purchase, raw materials are recorded as inventory at standard cost. b. In general, the production manager is responsible for the materials price variance. c. An unfavorable materials quantity variance occurs when the actual quantity used in production is less than the standard quantity allowed for the actual output of the period. d. If skilled workers with high hourly rates of pay are given duties that require little skill and call for lower hourly rates of pay, this will result in a favorable labor rate variance. e. The variable overhead efficiency variance does not actually measure how efficiently variable manufacturing overhead resources were used. O Statements d. and e. O None of the statements Statements a, and e. O Statements b. and d. Statement c