You have an Exchange Server 2010 organization. You plan to deploy two new Mailbox servers. 
Both Mailbox servers will be members of a database availability group （DAG）. You need to recommend a hard-disk configuration for the new servers. Your recommendation must meet the following requirements：.Maximize write performance
.Prevent a switchover if a single disk fails
Which disk configuration should you recommend？（）

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？（）