What are three required steps to configure DHCP snooping on a switch? (Choose three.)

A.
Configure the switch to insert and remove DHCP relay information (option-82 field) in forwarded DHCP request messages.

B.
Configure DHCP snooping globally.

C.
Configure the switch as a DHCP server.

D.
Configure DHCP snooping on an interface.

E.
Configure all interfaces as DHCP snooping trusted interfaces.

F.
Configure DHCP snooping on a VLAN or range of VLANs.

Explanation:

When you configure DHCP snooping on your switch, you are enabling the switch to differentiate untrusted interfaces from trusted interfaces. You must enable DHCP snooping globally before you can use DHCP snooping on a VLAN. You can enable DHCP snooping independently from other DHCP features.
To enable DHCP snooping, follow this procedure:

You can configure DHCP snooping for a single VLAN or a range of VLANs.

Reference:
www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.1/12ew/configuration/guide/dhcp.html#wp1073367