CompTIA A+ 220-902 Question G-21

A technician has 50 identical computers that need to be upgraded to the Windows 7 OS, and are capable of booting from the network. They are running a Gigabit network with a Windows deployment server. Which of the following will be the BEST to use in this scenario?

A. UEFI
B. Windows 7 DVD
C. PXE
D. USB flash