What version of the Cisco PIX Firewall is required to use the VPN accelerator card?

What version of the Cisco PIX Firewall is required to use the VPN accelerator card?

A.
version 5.3 or higher

B.
version 4.3 or higher

C.
version 6.3 or higher

D.
version 3.3 or higher

E.
version 2.3 or higher