Your company has a Microsoft Exchange Server 2019 hybrid deployment. Users in the advertising department and the editorial department of the company have mailboxes in Exchange Online. A company policy requires that the advertising department users and the editorial department users be segmented based on the following requirements: ? The advertising department users must not see the editorial department users in the global address list ? (GAL). ? The editorial department users must not see the advertising department users in the GAL. ? The editorial department users must be treated as external recipients of the advertising department users. ? The advertising department users must be treated as external recipients of the editorial department users. You need to recommend a solution that meets the requirements and minimize costs and effort. What should you recommend?