You'd better take these document

You'd better take these documents with you _____ you need them for the meeting.
A、unless
B、in case
C、until
D、so that
【正确答案】：B
【题目解析】：unless除非；in case以防万一；until直到；so that以至于句意：你最好带上这些文件以防开会时需要。