False is correct.

Retention policies in Cloud Storage are enforced based on each objects creation time and the configured retention period. When you set or publish a retention policy on a bucket existing objects do not get a new creation timestamp and therefore the policy does not retroactively change their retention state. New objects uploaded after the policy is set will be subject to the retention rules immediately according to their creation time and the buckets retention period.

True is incorrect because that option suggests the retention rules apply to all objects instantly and retroactively. That is not how Cloud Storage retention policies work since existing objects keep their original creation times and are not automatically given the same treatment as newly uploaded objects when the policy is added.

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