单选题

A (68) is a feature of the system or adescription of something the system is capable of doing in order to fulfill the system's purpose.
【正确答案】 B
【答案解析】[解析] 译文：需求反映了系统的特征或者是这样一种描述，它说明了系统为达到某种目标能够做的事情。