Historically one firm had reserved about 30% of its revenue every year for returns discounts and so forth but in 2007 this same firm reserved only about 9 percent with the effect that ___ (pick either one of 2 most correct)

A) inventory balances and cost of goods sold both decreased

B) inventory balances and cost of good sold both increased

C) customers bought less due to lower discounts

D) reported revenues were boosted

E) operating margin looked better