What methods can be used to move production data into a sandbox for testing purposes?

The correct method to move production data into a sandbox for testing purposes is to refresh a Full Sandbox. A Full Sandbox is a replica of your production environment, including the production data and metadata, allowing for comprehensive testing scenarios. When you refresh a Full Sandbox, you create a new copy of the current production data, which means that the sandbox will have the most up-to-date version of your production data and setup, making it ideal for testing.

Using the metadata API allows you to transfer metadata configurations rather than complete production data. This approach is useful for deployments but does not serve the purpose of moving production data into a sandbox directly. Requesting a Snapshot from Support isn’t a standard method for data transfer into sandboxes, as it doesn't provide a straightforward way to mirror production data into a sandbox environment. Refreshing a Copy Sandbox would also not be the right answer in this context, as it only copies data from another sandbox rather than directly from production. Thus, refreshing a Full Sandbox is the optimal option for ensuring that the testing environment reflects the most accurate production data available.