While testing a version of cloud native application, a new version is provided for Integration Testing, what should be followed in testing process?

$1-$ Complete testing current version and complete testing new version, but approve only release of new version for deployment

$2-$ Give strict requirement to developers, not to release any new version until current version is deployed$$

$3-$ Complete testing the current version, and approve current version for deployment and then move on to testing the new version$$

$4-$ Stop testing the current version, start testing the new version$$