The correct answer is -sV -O --script=all. The -sV option enables version detection, probing open ports to determine service/version info, while the -O option triggers OS detection. Combining these with --script=all applies a variety of scripts for further enumeration, including default and non-default scripts that check for a wide range of vulnerabilities and configurations, making it the most comprehensive choice for asset enumeration. -sn only performs host discovery, which would not enumerate open ports or services. --top-ports only scans the most common ports, which might miss out on less common but potentially critical ports. -Pn disables host discovery and should only be used when ensuring all ports are scanned regardless of the host being up.