Refer to the exhibit. DHCP snooping is enabled for selected VLANs to provide security on the network.  How do the switch ports handle the DHCP messages？（）

• A、Ports Fa2/1 and Fa2/2 source DHCP requests only. Port Fa3/1 is eligible to source all DHCP messages and respond to DHCP requests.
• B、Ports Fa2/1 and Fa2/2 respond to DHCP requests only. Port Fa3/1 is eligible to source all DHCP messages.
• C、Ports Fa2/1 and Fa2/2 are eligible to source all DHCP messages and respond to DHCP requests. Port Fa3/1 can source DHCP request only.
• D、All three ports， Fa2/1， Fa2/2， and Fa3/1， are eligible to source all DHCP messages and respond to DHCP requests.