An attacker is launching a DoS attack on the Company network using a hacking tool designed to  exhaust the IP address space available from the DHCP servers for a period of time.  Which  procedure would best defend against this type of attack？ （）

• A、 Configure only trusted interfaces with root guard.
• B、 Implement private VLANs （PVLANs） to carry only user traffic.
• C、 Implement private VLANs （PVLANs） to carry only DHCP traffic.
• D、 Configure only untrusted interfaces with root guard.
• E、 Configure DHCP spoofing on all ports that connect untrusted clients.
• F、 Configure DHCP snooping only on ports that connect trusted DHCP servers.
• G、 None of the other alternatives apply