The correct option is 201. This status code indicates that a new resource has been successfully created as a result of the POST request. It's commonly used in RESTful APIs when a new resource is added.

Security is a critical aspect in testing third-party API integrations, particularly when handling sensitive or personal data. It involves ensuring that proper measures such as encryption, authentication, and authorization are in place to protect the data from unauthorized access or breaches.

Providing detailed error messages in API design is essential for assisting developers in identifying and resolving issues. Clear and informative error messages help developers understand what went wrong, where the problem occurred, and how to fix it. This contributes to a more efficient debugging process and improves the overall developer experience when working with the API.

In API security testing, authentication mechanisms ensure that only authorized users or systems can access the API. This is a critical step in preventing unauthorized access to sensitive data or functionalities.

Performance testing in the context of APIs aims to evaluate the system's responsiveness, ensuring it meets the required performance criteria. It involves analyzing how well the API performs under various conditions, such as different loads and usage scenarios, to ensure optimal responsiveness in a production environment. This helps identify and address performance bottlenecks and ensures a seamless user experience.

When dealing with APIs having multiple interdependent parameters, it's crucial to test all possible combinations of parameters. This comprehensive approach ensures that the interactions between parameters are thoroughly examined, helping to identify potential issues in complex scenarios.

The HTTP status code "200 OK" indicates that the request has succeeded. This status code is returned when the server successfully processes the request and sends the requested resource back to the client. It is a standard response for successful HTTP requests.

API testing contributes to the monitoring and feedback loop by identifying performance bottlenecks. It helps in ensuring that APIs meet performance expectations and provides valuable insights for continuous improvement.

Data-driven testing is crucial for identifying edge cases in API functionality, particularly through boundary testing. By providing various inputs at the edge of acceptable ranges, testers can uncover potential issues and ensure the API behaves correctly in extreme scenarios. Options 1, 2, and 4 do play roles in testing but are not specifically focused on identifying edge cases.

In both positive and negative API testing, examining edge cases is crucial. Edge cases represent the extreme conditions or boundaries of input values. Testing these scenarios helps uncover potential vulnerabilities in the system, including unexpected behavior, security flaws, and performance issues that may not be evident under normal conditions.