According to Poter, which one of the following is the most powerful of the five forces .下列哪个是波特所说五种力量中影响力最大的一个 。
A、The bargaining power of suppliers 供应商议价力量
B、Bargaining Power of Consumers顾客的议价力量
C、Potential Entry of New Competitors潜在进入者的威胁
D、Rivalry Among Competing Firms现有竞争对手的竞争