The diagram shows sample configuration for Anti-Virus Checking for Incoming Email. Which one of the following is not a step to configure Anti-Virus checking for incoming email?

A.
Define rules that use the resource

B.
Create a gateway object to represent the Security Gateway

C.
Create an OPSEC Application object to represent the OPSEC Application server, and associate it with the host object

D.
Define an SMTP resource that uses the OPSEC Application object, and associate it with the OPSEC Application object

E.
Create a host object for the machine on which the third-party, OPSEC server application is installed