You have an Exchange Server 2003 organization.You install an Exchange Server 2010 Edge Transport server on the network.You need to ensure that the Edge Transport server can send and receive e-mail messages from the Internet for the organization.You configure the Exchange Server 2003 servers to send all e-mails for external recipients to the Edge Transport servers. What should you do next？（）

A. Create and configure a sharing policy.
B. Install the Exchange Server 2010 schema extensions.
Create an Edge Subscription file.Copy the file to the Exchange Server 2003 servers.
D. Create and configure a Send connector on the Edge Transport server.Create and configure a Receive connector on the Edge Transport server.