Which method focuses on testing all the infrastructure that supports the application, including networking, database functionality, and security?

The method that focuses on testing all the infrastructure that supports the application, including networking, database functionality, and security, aligns most closely with continuous monitoring. Continuous monitoring involves the ongoing observation of various system components and their interactions to ensure that everything is functioning correctly and securely. It underscores an environment where all aspects of the application and its infrastructure are continuously assessed for performance, vulnerabilities, and compliance with security policies. This enables teams to detect issues early and respond promptly to any anomalies or potential risks in the infrastructure that could affect the application's performance or security.

The continuous delivery method refers primarily to the practice of delivering software updates and new features to production in a systematic manner, rather than testing all aspects of the infrastructure. Continuous integration focuses on merging code changes from multiple contributors into a shared repository frequently, but does not directly test all infrastructure components. Continuous deployment automates the deployment process but is still a step after ensuring the code is stable and secure. Thus, the essence of infrastructure testing is more accurately captured in the context of continuous monitoring.