You're in a protected environment where USB ports and DVD drives are not permitted on workstations. You've just received ten new bare-metal workstations with PXE feature that need to be configured with Windows. How will you install Windows on these ten computers?

You can't use optical media to install Windows 10 because the workstations don't have DVD drives, and you're unlikely to be able to utilize an external drive because there are no USB ports. Internet-based installation necessitates the ability to start and connect to the Internet, so you'd need an operating system already installed, and the question specifies that they are bare-metal devices. You're left with a network installation that only supports PXE boot.