The standard costs and actual costs for direct materials for the manufacture of 2,350 actual units of product are as follows: Standard Costs Direct materials 2,350 kilograms at $8.50 Actual Costs Direct materials 2,400 kilograms at $8.30 The direct materials quantity variance is Oa. $340 unfavorable Ob. $425 unfavorable Oc. $425 favorable Od. $340 favorable