Which of the following is a common characteristic of most project life cycle descriptions ？（）
A．Cost and staffing are low at start，higher towards the end of implementatioand drop rapidly as the project nears completio
B．The probability of successfully completing the project is highest at the start of the projec
C．Stakeholders have the most influence on the final characteristics of the product at the end of the projec
D．Risk and uncertainty are lowest at the start of the projec