The function key that is used to start Safe Mode in Windows NT is none of the above, because Windows NT does not support Safe Mode. Safe Mode is a diagnostic mode of Windows that starts the system with minimal drivers and services, allowing the user to troubleshoot problems and restore the system to anormal state1. Safe Mode was introduced in Windows 95 and later versions, but not in Windows NT 4.0 and earlier2.
The other options are incorrect for the following reasons:
F10. This function key is used to access the Recovery Console in Windows XP, which is a command-line interface that allows the user to perform various administrative tasks, such as repairing the boot sector, restoring the registry, or copying files3. The Recovery Console is not the same as Safe Mode, and it is not available in Windows NT.
F8. This function key is used to access the Advanced Boot Options menu in Windows Vista and later versions, which allows the user to choose from various boot modes, including Safe Mode, LastKnown Good Configuration, Debugging Mode, and others4. In Windows NT, pressing F8 during startup only displays a simple menu with three options: Normal, VGA mode, and Boot Logging5. None of these options are equivalent to Safe Mode.
F6. This function key is used to load additional drivers during the installation of Windows, such as SCSI or RAID drivers, from a floppy disk or a USB flash drive6. This function key has nothing to do with Safe Mode, and it is not relevant after the installation is completed.
References:
Start your PC in safe mode in Windows - Microsoft Support
How do you boot NT into safe mode? | TechRepublic
How to install the Recovery Console to your hard disk
Advanced startup options (including safe mode) - Windows Help
How to Boot Windows NT in Safe Mode
How to install third-party SCSI or RAID driver
