The correct selection is A. A deployment train should not unintentionally span incompatible Salesforce release versions. During a preview window, sandboxes used together for promotion should be deliberately aligned so the same release artifact is tested against a consistent platform version before production deployment. From a release perspective, approved functionality must be isolated from unfinished work and promoted through a predictable, auditable path. Release calendars, validation, stakeholder approval, rollback planning, and branch discipline reduce the risk that a technically correct change becomes an operational failure during production promotion. The rejected alternatives weaken release control by mixing development states, skipping required validation, or treating production promotion as an ad hoc administrative task. For this scenario, the decisive point is therefore the platform behavior represented by the selected option (A. Refresh all non-preview sandboxes during the release preview window.). Applying that rule consistently keeps the implementation aligned with Salesforce-supported lifecycle practices and makes the resulting change easier to review, validate, and operate across environments.

Study Guide reference: Releasing --- release management; branching and hotfixes; production readiness; rollback strategy; seasonal releases; approvals.