Final answer:
An operating system requires a digital license activation to verify its legitimacy and adherence to the EULA, unlike mechanical pencils, analog watches, or hardcover books.
Step-by-step explanation:
The component that would require a digital license activation is the operating system. A digital license is a method of activation for software that verifies that a copy of a program is legitimate and has not been used on more devices than the software's End User License Agreement (EULA) allows. In this context, only an operating system like Windows, macOS, or Linux would necessitate the use of such a license. Mechanical pencils, analog watches, and hardcover books do not require software to function and therefore do not need a digital license.