A company incurred total manufacturing costs of $500,000 during 2007. Work in process inventories at the beginning and end of 2007 were $100,000 and $50,000 respectively. If finished goods inventories at the beginning and end of 2007 were $30,000 and $80,000 respectively, what was the cost of goods sold for the period?

A) 450,000 B) 500,000 C) 520,000 D) 550,000 E) 580,000

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