The following data have been taken from the accounting records of Rayburn Corporation for the current year. Sales $1,980 Selling expenses 350 Manufacturing overhead 460 Direct labor 400 Administrative expenses 500 Purchases of Direct materials 240 Finished goods inventory, beginning 240 Finished goods inventory, ending 320 Direct materials inventory, beginning 100 Direct materials inventory, ending 140 Work in process inventory, beginning 140 Work in process inventory, ending 100 What was the cost of the direct materials used in production during the year? a) $180 b) $140 c) $340 d) $200