Question

barcode scanners, printers, routers, and smartphones are examples of:
a. the graphical user interface.
b. system software.
c. an extranet.
d. hardware.

Explanation:

Barcode scanners, printers, routers, and smartphones are physical devices. Hardware refers to the physical components of a computer system or network. The graphical user interface (a) is a software - related concept for interacting with a system. System software (b) is a set of programs that manage computer hardware. An extranet (c) is a network that extends a private network to outside entities. So, these devices are examples of hardware.

Answer:

D. hardware.