单项选择题 Which of the following RAID levels would be the BEST choice if performance was the only determining factor?（）

单项选择题 Multiple expansion cards are installed in a rack mount 1U server. All expansion cards stop working simultaneously.  Which of the following is the MOST likely cause of the problem？（）

单项选择题 Which of the following offers the MOST redundancy for a system but is also very costly?（）