Which of the following describes proprietary software?

Proprietary software is characterized by its development under specific licenses and restrictions. This type of software is owned by an individual or a company, which means that the source code is usually kept secret and users are not permitted to modify it. The licensing agreements that come with proprietary software often stipulate the terms under which it can be used, which can include limitations on copying, sharing, and creating derivative works.

In contrast, the other choices describe aspects of different software models. The first choice relates to open-source software, where users can freely modify the software. The second choice suggests a more open model typically associated with free or open-source software, which allows for fewer restrictions on usage. The last option implies that a software is seldom updated, which isn’t a definitive characteristic of proprietary software, as many proprietary applications receive regular updates and maintenance from the developer. Thus, the defining factor that makes choice C the correct answer is its emphasis on the ownership and control inherent in proprietary software licensing.