Which of the following uses a handheld operating system?

A. supercomputer
B. personal computer
C. Laptop
D. PDA

A handheld computer is a computer that can conveniently be stored in a pocket (of sufficient size) and used while you’re holding it. Today’s handheld computers, which are also called personal digital assistants (PDAs), can be divided into those that accept handwriting as input and those with small keyboards