Pending

Explanation: when we are using client authentication with all the setting for fully automatic authentication, you can authenticate all the protocols, it doesn't matters if the protocol supports authentication. See the Client Authentication features in the Secure knowledge base of Checkpoint for more information.
Incorrect AnswersB:You can authenticate all the protocol whatever or not they support authentication, remember, this is client authentication.

Explanation: this is the main difference between the listed firewall technologies, the statefull inspection, because with it, we can see the packet before it goes to the Layer 3 of the OSI model (Network Layer = O.S TCP/IP Protocol Stack), this technology has the most access to the TCP/IP packet including the top layers.
Incorrect Answers
A:This is configurable and is not a difference between the listed firewall technologies.
C:VPN1/Firewall 1 has full access to the packet headers.
D:This is not a difference.
E:All firewall technologies has access to the network, you define what are your key locations inside it, then, you put the firewall to make that "key locations" pass the traffic through it.