Your network has two main offices.Each office is configured as a separate Active Directory site named Site1 and Site2.Each site contains an Exchange Server 2010 Hub Transport server.You need to prevent a user from Site1 from sending an e-mail message that contains the word budget to a user from Sit.What should you do？（）

• A、From a Hub Transport server in Site1， create a transport rule.
• B、From a Hub Transport server in Site1， configure the sender filtering feature.
• C、From a Hub Transport server in Site2， configure the content filtering feature.
• D、From a Hub Transport server in Site2， modify the properties of the Client Receive connector.