What is the effect of entering the ip dhcp snooping limit rate 6 configuration command on a switch?

Question:
What is the effect of entering the ip dhcp snooping limit rate 6 configuration command on a switch?

• It displays the IP-to-MAC address associations for switch interfaces.
• It enables port security globally on the switch.
• It restricts the number of discovery messages, per second, to be received on the interface.
• It dynamically learns the L2 address and copies it to the running configuration.

Exam with this question: Switching, Routing, and Wireless Essentials ( Version 7.00) - SRWE Final Exam