You are the enterprise administrator for an Exchange Server 2010 organization. All users run Microsoft Office Outlook 2010. You are designing a sharing solution for your organization and a partner organization. The partner organization also uses Exchange Server 2010. You need to recommend a strategy for sharing information with the partner organization to meet the following requirements： .Provide cross-organizational access to user contacts .Provide cross-organizational access to free\busy information What should you recommend？（）
- ACreating cross-forest trusts
- BImplementing Federated Sharing
- CImplementing Microsoft Identify Lifecycle Manager （ILM） 2007
- DRunning the Microsoft Exchange Inter-Organization Replication tool