What file is used for configuring properties in a Mule application?

The correct choice for configuring properties in a Mule application is the application.properties file. This file is used to define application-specific configurations and settings as key-value pairs. It enables developers to manage variables like endpoints, credentials, and environment-specific configurations that can be used throughout the application.

Using the application.properties file allows for separating configuration from code, which is a best practice for keeping applications flexible and maintainable. This is especially useful in scenarios where you need to deploy the same application across different environments (development, staging, production) without changing the code itself—only the properties file needs to be updated.

Other options like mule-config.xml are typically used for defining flow configurations or components but do not serve the same purpose as the application.properties file for managing properties and settings. Similarly, mule-artifact.json is used to define metadata about the Mule application, while settings.json is not a standard configuration file used in Mule applications for properties management. Thus, the application.properties file is the appropriate choice for configuring properties in a Mule application.