11. EKPN Co. produces wooden boxes. The company's standards per box require 6 boards, each costing $10 per board, and half of an hour of direct labour. The standard labour rate is $15 per hour. In August, EKPN Co. Purchased 12,000 boards for a total cost of $123,000. It used 11,500 boards to manufacture 1,900 boxes. Total labour hours were 1,000 hours, and total labour costs were $16,250. What was the labour quantity variance for August? a) $750 F b) $750 u c) $13,500 F d) $13,500 u