请各位高手看看我对一个GWD逻辑的解释是不是正确？

Denoma, a major consumer-electronics maker, had a sizeable decline in sales revenue for its most recent fiscal year.  This result appears surprising, because electronics retailers report that although their overall sales were considerably lower than in the previous year, their sales revenue from Denoma models actually grew, largely thanks to some innovative and popular models that Denoma introduced.

Which of the following, if true, does most to explain the apparently surprising result?

1. Because of the need to educate the public about its new models’ capabilities, Denoma’s advertising spending was higher than normal over the period.
2. For the period at issue, Denoma’s major competitors reported declines in revenue that were, in percentage terms, greater than Denoma’s.
3. A significant proportion of Denoma’s revenue comes from making components for other consumer-electronics manufacturers.
4. Unlike some of its major competitors, Denoma has no lines of business outside consumer electronics to provide revenue when retail sales of consumer electronics are weak.
5. During the period, consumer-electronics retailers sold remaining units of Denoma’s superseded models at prices that were deeply discounted from those models’ original prices.

我做的时候错选了A 正确答案是C， 是不是因为文章中提到的sales 和sales revenue 其实是一样的意思，而且文中已经讲了在retailer那D公司的销售情况是上升的，所以A中再提到广告投入的话就与文中的意思不一致了因为文章已经讲了销售上升，我们要做的是找出一个另外的原因说明surprise那就是C中的解释 因为作为D公司收入的大部分来源的销往其他公司的components销售很差。 我这样的解释对吗？？