A company developed the following per-unit standards for its product: 5 kilograms of direct materials at $2 per kilogram. Last month, 1,000 kilograms of direct materials were purchased for $3000. Also last month, 660 kilograms of direct materials were used to produce 122 units. What was the direct materials quantity variance for last month? $100 unfavourable O $100 favourable O $680 unfavourable O $680 favourable