You are a messaging professional. Your company plans to upgrade from a Microsoft Exchange Server 2003 messaging system to a Microsoft Exchange Server 2007 messaging system.

The current Exchange Server 2003 organization consists of three offices. Each office is a separate Microsoft Active Directory site. Each office has a Clustered Mailbox server.

You are planning the Exchange Server 2007 computer and server role placements for the upgrade. The mailboxes of each office must be stored on servers located in the respective office.

You need to ensure that the existing level of service availability is unaffected by the upgrade. You also need to ensure that on completion of the upgrade, there is full messaging functionality in each Active Directory site.

Which two actions should you perform to ensure that on completion of the upgrade, there is full messaging functionality in each Active Directory site.? (Each correct answer presents part of the solution. Choose two.)

A.
Install two Exchange Server 2007 computers in each site. Configure the computers as a Single Copy Cluster (SCC) clustered Mailbox server.

B.
Install two Exchange Server 2007 computers in each site. In each site, configure the Hub Transport server role and the Client Access Server role on both the computers.

C.
Install one Exchange Server 2007 computer in each site. In each site, configure the Edge Transport server role on the computer.

D.
Install one Exchange Server 2007 computer in each site. In each site, configure the Hub Transport server role and the Client Access Server role on the computer.

E.
Install one Exchange Server 2007 computer in each site. In each site, configure the Hub Transport server role, the Client Access Server role, and the Mailbox server role on the computer. Configure each mailbox database in a separate storage group. Enable Local Continuous Replication (LCR) on the storage groups.