Make sure all the members of our club arrive on time, _______ th

Make sure all the members of our club arrive on time, _______ there will be little time left for the discussion.
A、however
B、while
C、therefore
D、otherwise
【正确答案】：D
【题目解析】：这句话阿意思是：要确保俱乐部的所有成员都准时到达，否则就会剩下很少讨论的时间。由此可知，这句话的前后部分并不是因果、转折关系，也不存在对比，所以排除前三项，选D。