Which testing method assesses the security of an API?

• A. Functional Testing
• B. UI Testing
• C. Security Testing
• D. Performance Testing

Answer: (C)

The selected answer accurately identifies the method that directly evaluates the security of an API. Security testing focuses on identifying vulnerabilities, threats, and risks within the software, particularly in how it handles sensitive data and manages user authentication and authorization. This method seeks to ensure that the API is resistant to various kinds of attacks, such as SQL injections, cross-site scripting, and other malicious exploits that could compromise the system's integrity or the confidentiality of the data.

Functional testing, while important, is primarily concerned with verifying that the API behaves as expected according to its specified behavior and functional requirements. It does not specifically address security aspects. Similarly, UI testing evaluates the user interface and user experience, which is not relevant to assessing API security. Lastly, performance testing involves measuring the API's responsiveness, reliability, and scalability under various loads, rather than its security features.

In summary, security testing is essential for safeguarding APIs, making the chosen answer the most appropriate for this question.