The df command indicates that a filesystem is full， however， the du command indicates that not all space is allocated. 
How would the system administrator isolate the discrepancy（）

everal people in an finance customer IT department are asking for fileset updates that the 
system administrator received from IBM earlier that day on CD-ROM. The system administrator created an install directory on their machine and made it available to everyone. 
Which of the following commands will allow the system administrator to copy the images from an IBM update CD-ROM to the install directory（）