An essential difference between the operating system that runs a typical desktop computer and the operating system that runs a typical PDA is that .......
Options:
A . the desktop OS has a graphical user interface whereas the PDA OS does not.
B . the desktop OS can run several programs simultaneously whereas the PDA OS cannot.
C . the desktop OS manages hardware resources whereas the PDA OS does not.
D . the desktop computer has an OS whereas a PDA does not.
