A network engineer is working on securing the environment in the screened subnet.

Comprehensive and Detailed Explanation From Exact Extract:

nmap -A performs aggressive scanning, which includes OS detection, version detection, script scanning, and traceroute — exactly what is required in this case. It's the most effective and commonly used tool for comprehensive network reconnaissance prior to security testing.

Relevant Extract from CompTIA CloudNetX CNX-001 Study Guide — under “Security Scanning and Reconnaissance Tools”:

“Nmap supports comprehensive scanning options, including OS fingerprinting, service version detection, and port scanning, enabling detailed pre-penetration testing assessments.”

Other options:

A. tcpdump is for packet capture, not scanning.

C. nc (netcat) is a port scanning tool, but it lacks OS/app detection.

D. hping3 is a packet generator, not suitable for full-service scanning.

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