Your network contains 20 offices. Each office contains 1，000 users. The users access their e-mail messages by using Microsoft Office Outlook. You have an Exchange Server 2010 organization. You need to recommend an Exchange Server solution that meets the following requirements： .Ensures that users in each office download the list of recipients for their office only .Ensures that users in each office can send e-mail messages to any user in the organization What should you recommend？（）

A. Create 20 new address lists and 20 offline address books （OABs）.
B. Create 20 new managed folder mailbox policies and 20 e-mail address policies.
Create 20 new dynamic distribution groups， and then create 20 new global address lists （GALs）.
D. Create 20 new mailbox databases， and then move the mailboxes from each office to a separatemailbox database.