An access list has been designed to prevent Telnet traffic from the Graphics Department from reaching the HR server attached to the Eastfield router but allow Telnet traffic to other destinations…

Placing the ACL on Westfield is less efficient because it is farther from the HR server, and the deny rule 'any any eq 23' would also block Telnet to all other destinations from that point forward.

Placing the ACL on Eastfield - the router directly connected to the HR server - is most efficient because packets are filtered at the last possible hop, minimizing unnecessary processing on upstream routers.

The e0 (Ethernet 0) interface on Eastfield is the interface connected to the LAN segment where the HR server resides, making it the correct interface to apply the ACL.

The 'in' direction on e0 would filter traffic arriving from the HR server's LAN segment toward the router, which is the wrong direction to block inbound Telnet requests targeting the server.

The inbound direction on Eastfield's e0 processes traffic coming from the server side toward the router, not traffic flowing from the network toward the HR server.

Applying the ACL in the outbound direction on e0 means it filters traffic as it exits the router toward the HR server's LAN, blocking Telnet destined for the server while permitting all other traffic.