You need to ensure that anti-spam filtering is enabled for your organization after the transition to Exchange Server 2007

You are the messaging engineer for your company. Your network contains a single Microsoft Exchange Server 2003 server with Service Pack 2 installed. The Intelligent Message Filter has been enabled on the Exchange Server 2003 server. You plan to transition your messaging environment from Exchange Server 2003 to Exchange Server 2007. You do not plan to deploy an Edge Transport server. You need to ensure that anti-spam filtering is enabled for your organization after the transition to Exchange Server 2007. What should you do?

A.
Configure sender reputation.

B.
Run the AntispamCommon.ps1 Exchange Management Shell script.

C.
Run the Install-AntispamAgents.ps1 Exchange Management Shell script.

D.
Configure a transport rule that drops all messages with a spam confidence level of five or higher.

Explanation:
To install and enable anti-spam features on a Hub server, run the Install-AntispamAgents.psi script, located in the %system drive%/Program Files/Microsoft/Exchange Server/Scripts folder. Then, restart the Exchange Transport Service. The following anti-spam features are enabled: Connection filtering,
Content filtering, Sender ID, Sender filtering, Recipient filtering, Sender reputation.

http://technet.microsoft.com/en-us/library/bb201691.aspx

AntispamCommon.ps1 is referenced by other 2007 anti-spam scripts and not intended to be run directly.