The standard costs and actual costs for direct materials for the manufacture of 2,680 actual units of product are as follows: Direct materials Standard Costs 2,680 kilograms @$8.90 Direct materials Actual Costs 2,800 kilograms @ $8.15 The direct materials quantity variance is Oa. $1,068 favorable Ob. $1,068 unfavorable Oc. $854 unfavorable Od. $854 favorable