In configuration management, a configuration item is:

A.
A component whose state is to be recorded and against which
changes are to be progressed.

B.
The version of the operating system that is operating on the workstation
that provides information security services.

C.
Aseries of files that contains sensitive information.

D.
The network architecture used by the organization.

Explanation:
Acomponent whose state is to be recorded and against which changes are to be progresseD.
The other answers are incorrect by the definition of a configuration item.