Which command line includes both a TCP connect scan and operating system detection?

• A. nmap -sS -O ip
• B. nmap -sT -O ip
• C. nmap -sT -A ip
• D. nmap -O -sS ip

Answer: (B)

Combining a TCP connect scan with OS fingerprinting. A TCP connect scan uses -sT, which completes the TCP handshake with the target, and OS detection uses -O to fingerprint the remote host’s operating system. The line that explicitly combines both is nmap -sT -O ip, giving a connect-based scan plus dedicated OS detection. Other options miss this exact pairing: one uses a different scan type like -sS (SYN stealth) and thus isn’t a connect scan, while another option adds broader features with -A (which includes OS detection but also version/script capabilities), or uses -O with -sS, which again lacks a connect scan.