Many manufacturers were accused of concentrating too heavily on cost reduction, often at the _____ of the quality of their products.

【正确答案】 C

【答案解析】解析：考查名词辨析。expense表示“价钱，花费；(pl.)开支”，意为“由……付费；以……为代价”，符合题意，为正确答案。expansion意为“扩大，扩展”；exposure意为“暴露；揭发”；expectation意为“期待；(pl.)前程”。