With regard to the drivers behind Application Grid based computing， consider the following statements and indicate which is TRUE:// （）  I. data center complexity leads to lack of predictability making it difficult if not impossible to guarantee quality of service  II. data centers must do more with less and find a way to better utilize existing capacity  III. growth means added complexity

• A、 I and II
• B、 I and III
• C、 II and III
• D、 I， II and III