When should senior management perform periodic project reviews? a.Completion of a milestone. b.Completion of each life cycle phase. c.When one functional group completes their tasks. d.When an activity interface point is reached. 高层管理在何时进行阶段性的项目检查? A完成一个里程碑时 B完成项目生命期的每个阶段时 C当一个职能团队完成他们的任务时 D在到达活动的界面时 正确答案是什么,其他为什么不正确?