The correct command -sV enables version detection to discover service version information, which is useful for creating a detailed inventory. Using -T2 along with -sV slows down the scan to reduce network load and potential disruption. Option A's -O flag is for OS detection but does not reduce the scan aggressiveness, and -T4 would increase the scan speed, likely causing more network disruption. Option B's -sn flag would only perform a ping scan, which doesn't gather service or OS version details. Option C's -Pn skips the discovery phase, which is not suitable when a detailed inventory is needed.