Which of the following will boot from a network-hosted ISO image at power on?

PXE (Preboot Execution Environment) uses DHCP to obtain a network address and TFTP to download a bootloader at power-on, enabling the system to boot from a network-hosted ISO or image entirely before the local storage is involved.

FTP is an application-layer file transfer protocol and has no role in or awareness of the system boot process.

iSCSI provides block-level access to remote storage but is not a preboot network boot protocol and cannot independently initiate booting from an ISO image at power-on.

NFS is a file-sharing protocol for mounting remote directories at the OS level and cannot function before an OS is already loaded.