Final answer:
The Sandbox release allows certain users/financial institutions to preview new features, enhancements, and defect solutions.
Step-by-step explanation:
The release that allows certain users/financial institutions to preview new features, enhancements, and defect solutions is the Sandbox release. The Sandbox is a testing environment where users can experiment with new features before they are rolled out to the general public. This allows them to identify any issues or bugs and provide feedback to the developers.