According to the FortiOS 7.6 Administration Guide and Fortinet hardware acceleration (NTurbo) documentation, the correct answer is A.

What NTurbo Is (FortiOS 7.6 – Verified)

NTurbo is a hardware-based acceleration feature available on specific FortiGate models. It is designed to improve antivirus and IPS performance when operating in flow-based inspection mode.

NTurbo works by creating a fast, optimized data path between:

FortiGate ingress interface

IPS/AV engine

FortiGate egress interface

This minimizes CPU involvement and reduces packet traversal overhead.

Why Option A Is Correct

A. For flow-based inspection, NTurbo establishes a dedicated data path to redirect traffic between the IPS engine and FortiGate ingress and egress interfaces.

This is exactly how NTurbo works, as documented:

NTurbo applies to flow-based inspection only

It accelerates IPS and antivirus scanning

It creates a dedicated fast path that bypasses unnecessary processing steps

This significantly improves throughput and lowers latency

This description matches Fortinet’s official explanation of NTurbo.

Why the Other Options Are Incorrect

B. NTurbo creates two inspection sessions

Incorrect. NTurbo does not duplicate sessions; it optimizes the packet path.

C. NTurbo offloads traffic to the content processor (proxy-based)

Incorrect. NTurbo does not apply to proxy-based inspection and does not offload to content processors.

D. NTurbo buffers the whole file and then sends it to the antivirus engine

Incorrect. Buffering entire files is a proxy-based behavior, not NTurbo.