Which three choices are required for the boot process for a Cisco IP phone? (Choose three.)

TFTP is required because the IP phone downloads its firmware binary and XML configuration file from the TFTP server address provided by DHCP option 150 or 66 - without TFTP, the phone cannot obtain its programming.

DHCP is required to assign the phone an IP address, subnet mask, default gateway, and critically the TFTP server IP via option 150 or 66 - without DHCP, the phone cannot reach any other boot service.

Voice VLAN is required so that the access switch can signal the correct VLAN to the phone via CDP or LLDP, placing the phone's traffic on the proper Layer 2 segment for QoS and reachability to call control infrastructure.

A routing protocol is not required for the phone boot process because the phone only needs IP reachability to the DHCP and TFTP servers, which can be provided by a simple default route or a single flat subnet.

TCP/IP is the internal protocol stack the phone itself uses, but it is not an external infrastructure service that must be provisioned to support the boot process.

PortFast is an STP optimization that reduces port convergence time and is recommended for IP phone ports, but the phone can still complete its boot sequence without it - just with a longer delay before the port forwards.