单选题

During the project, requirements change for a variety of reasons. As needs change and as work proceeds, additional requirements are derived and changes may have to be made to the existing requirements. It is essential to manage these additions and changes efficiently and effectively. To effectively analyze the impact of the changes, it is necessary that the source of each requirement is known and the rationale for any change is documented. The project manager may, however, want to track appropriate measures of requirements volatility to judge whether new or revised（）are necessary.

A proceedings

B controls

C forecastings

D Prelibations

解析： 该题的关键词为"appropriate measures、 requirements volatility"，其语句结构为"The project manager（主{吾） may, however, want to track（谓{吾） appropriate measures of requirements volatility（宾语） to judge whether new or revised（）are necessary（目的状语从句）"，含义为"项目经理也许会跟踪需求变化的相关度量，以判断是否应该调整的或者新的什么"，因为整段文字讨论的内容都集中于需求变更管理，所以只分析最后一句即可，根据题意，应该在空白处填写"措施"一类的词汇，排除之后只有选项B比较适合，选项A、C和D都可以排除，尤其是选项D是一个很生僻的词汇，含义为"尝试"。