Which switch enables version detection to determine the service running on a port?

• A. -sV --version-intensity
• B. -sV --allports
• C. -A
• D. -sV

Answer: (D)

Version detection is activated with the -sV switch. This tells Nmap to probe the open ports and identify the exact service and its version running behind each port. Adding --version-intensity just makes the probing deeper or broader, but the fundamental capability to detect services comes from -sV itself. Other options don’t directly control version detection: scanning all ports (--allports) changes which ports are tested, and a broader scan (-A) includes version detection as part of multiple checks but isn’t the specific switch that enables it. So the direct and precise way to determine the service and its version on a port is -sV.