The following additional information is available for the materials costs : Standard cost per unit produced: 3 liters @ $2.50 per liter Actual use of raw materials 19,000 liters @ $4.00 per liter The materials price and materials quantity variances are: a. $33,300 U materials price variance and $12,800 F materials quantity variance

b. $28,500 U materials price variance and $8,000 F materials quantity variance

c. $28,500 F materials price variance and $8,000 U materials quantity variance

d. None of the above