Which statement best describes public APIs?

Public APIs are designed to facilitate access to specific services or data for external developers and applications, enabling integration and interaction across different systems. They provide a controlled means for third parties to utilize the services offered by a company. This controlled access often includes some form of authentication and adherence to usage policies, allowing for secure and manageable interactions with the API.

Option B is correct because it encapsulates the fundamental purpose of public APIs: they enable external access while maintaining certain control measures to protect the underlying data and systems. Such access is beneficial for promoting broader usage and supporting the development of innovative applications that leverage the data and functionality exposed via the API.

Other statements do not accurately capture the essence of public APIs. For instance, limiting access to network engineers would contradict the public nature of these APIs. The assertion that public APIs do not require documentation is misleading; proper documentation is crucial for external developers to understand how to interact with the API effectively. Similarly, stating that public APIs are only usable by specific applications does not align with the idea of "public," as they should be accessible to a wide range of applications and developers.