Which of the following conclusions is most appropriate to draw to describe why du shows fewer blocks used than df?（）

• A、 The df command only counts the number of disk blocks and superblocks. 
• B、 The df command ignores space used for inodes, gnodes, and vnodes.
• C、 The du command does not take into account filesystem metadata. 
• D、 The du command counts indirect blocks and superblocks in its calculations.