As a rule of thumb for QA （Quality Assurance） activities， how many hours of downstream QA （Quality Assurance） costs are saved for each hour spent on technical reviews early in the project？（）

A.Probability-Impact matrix
B.Pareto chart
C.R-Chart
D.PERT （Program Evaluation and Review Technique） analysis

A.Requiring stakeholders to sign-off on project plan components
B.Requesting input from all stakeholders during the planning process
C.Providing an open line of communication regarding the project
D.Clearly illustrating how the project relates to the company’s objectives