Which of the following headers is part of the load testing parameters?

The load script name is a fundamental component of load testing parameters because it defines the specific script used to simulate user behavior and interactions with the application under test. This script is designed to outline the scenarios that will be executed during the testing process, such as the number of virtual users, the pacing between requests, and the overall workload model. Having a designated load script ensures consistency in testing conditions and allows for repeatable and comparable results across different load tests.

In contrast, the other options represent outcomes or messages encountered during the testing process rather than parameters that define how the load test is conducted. For instance, the response code indicates the server's reply to a request, while the database connection string pertains to how the application connects to its database. Lastly, an error message is a feedback mechanism that indicates failures during the testing process, but it does not directly influence the configuration of the test itself like the load script name does.