The customer is very worried because an important milestone has been missed and the initial prototype contains errors. To avoid this problem, what should the project manager do in advance? 因为漏掉一个重要里程碑且初始原型包含错误，客户十分担心。若要避免这个问题，项目经理应该事先做什么？ ◑A.Develop a quality checklist制定质量核对单 ◑B.Create a risk register创建风险登记册 ◑C.Issuing a change request签发变更请求 ◑D.Apply the prevention is better than cure.应用预防胜于检查
