Which deployment method allows selection of a test level before submission?

The correct choice is Manual, as this deployment method provides a user interface that allows users to specify a test level prior to submitting the deployment. In a manual deployment process, users can make deliberate choices regarding various parameters, including the scope of the deployment, which encompasses the selection of a specific test level. This flexibility allows for more control over the deployment environment, ensuring that the appropriate tests are executed based on the project's current needs.

In contrast, the other deployment methods have different characteristics. Automated deployments typically run predefined scripts without user intervention, limiting the options for user-selectable parameters such as the test level. Background and synchronous deployments both focus on the execution of processes without the same degree of manual input, primarily targeting efficiency rather than user-specified selections. Therefore, these alternatives do not allow for the selection of a test level before submitting, making Manual the unique option that facilitates user engagement and choice.