For deployment in multiple environments, how can a consistent application configuration be achieved across projects?

The correct approach to achieving a consistent application configuration across multiple environments is to configure a metadata key in each project to hold the environment value for application configuration. This method allows you to centralize your configuration data, ensuring that all instances in different projects can reference the same key-value pairs for their environment settings.

By using metadata keys, you can systematically and programmatically manage the configuration without the need for extensive manual intervention each time you deploy an application across different projects. It effectively standardizes configuration management, which is crucial for maintaining consistency, especially in development and production environments where differences can lead to errors or unexpected behavior.

This option also simplifies the process of updating configurations, as you can change the value in one place rather than needing to adjust settings in multiple scripts or settings across various instances. This leads to improved maintainability and reduced risk of discrepancies that can arise from human error during manual configuration.

The other methods, while potentially valid under specific circumstances, do not offer the same level of centralized management and scalability that metadata provides, making them less effective for ensuring consistency in application configurations across multiple projects.