Answer:
(c) Router Delay
Step-by-step explanation:
The network layer of the TCP/IP provides a mechanism or tool for troubleshooting and error messaging called Internet Control Message Protocol (ICMP). Network layer devices such as routers may use this tool to communicate errors especially if there is an issue delivering data packets.
Some of these error messages are;
i. Source Route Failed
ii. Source Host Isolated
iii. Network Unreachable
iv. Host Unreachable
v. Destination Network Unknown
vi. Destination Host unknown
Note:
Router delay is not one of the error messages identified by the ICMP.