What must you do to provide SPI to your mobile users?

The workstations on your network utilize Windows XP(service pack 2 or later). Many users take their laptops on the road. You are very concerned about the security and want to have a robust firewall solution for mobile users. You have decided that all your firewalls to use the Stateful Packet Inspection (SPI) method.
What must you do to provide SPI to your mobile users?

A.
You must purchase a third party firewall solutionfor your mobile users.

B.
Do nothing. Windows XP service pack 2 has a firewall turned on by default.

C.
Configure the Windows XP firewall to use SPI.

D.
Download the SPI template from Microsoft.