As Europe’s economy has 【soured】, free-market ideas that are new

As Europe’s economy has 【soured】, free-market ideas that are new to much of Europe face new challenges.
A、increased
B、declined
C、sky-rocketed
D、tasted
【正确答案】：B
【题目解析】：sour在这里意为“下降”；increase增加；decline下降；sky-rocket暴增；taste体验；故选B。