Their business flourished at its new location a year later owing to their joint efforts and hard work.

【正确答案】 C

【答案解析】解析：译文为：一年以后，因为他们的共同努力以及辛勤劳动，他们在新址开的店生意兴隆。flourished繁荣。prevail流行；fail失败，破产；boom迅速成长，日益繁荣；shrank的动词原型为shrink，意为“收缩，减少”。