SecureXL improves non-encrypted firewall traffic throughput and encrypted VPN traffic throughput.

SecureXL is a performance-enhancing technology used in Check Point firewalls. It improves the throughput of both non-encrypted firewall traffic and encrypted VPN traffic. The statement in option C is true because SecureXL does improve both types of traffic by offloading processing to dedicated hardware acceleration, optimizing firewall and VPN operations.

Option C correctly states that SecureXL improves this traffic, making it the verified answer.

References: Check Point Certified Security Expert (CCSE) R81 documentation and learning resources.