Which three commands can be used to harden a switch?

Which three commands can be used to harden a switch? (Choose three.)

A.
switch(config-if)# spanning-tree bpdufilter enable

B.
switch(config)# ip dhcp snooping

C.
switch(config)# errdisable recovery interval 900

D.
switch(config-if)# spanning-tree guard root

E.
switch(config-if)# spanning-tree bpduguard disable

F.
switch(config-if)# no cdp enable