Your question is Cisco Networking Fundamentals. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
Explain what ARP and RARP are and how they work in a network.
Describe the packet flow, address mappings, caching behavior, and broadcast or unicast behavior for each protocol. Explain why RARP is largely obsolete, identify relevant security risks such as ARP spoofing, and name practical Cisco-based mitigations.