Answer:  A 

Explanation:

Whenever logging is configured on the routers, we need to specify the level of logging that need to be enabled on the router. There are 7 different levels of logging can be configured on the router. Below are the various levels defined by Cisco:

- Level 0 refers to the system unstable state or emergencies only. Whatever logs that will be generated by the router will have syslog definition starting with LOG_EMERG.

- Level 1 refers to situations where alerts are generated and immediate actions are needed to keep the network stable. Here the logs will be created starting with the keyword LOG_ALERT.

- Level 2 refers to the critical situations and syslog definitions start with LOG_CRIT.

- Level 3 refers to Error conditions on the router. The syslog definitions start with LOG_ERR.

- Level 4 refers to the warning conditions. These are generated when warning conditions occur on the router. The syslog definition starts with LOG_WARNING

- Level 5 refers to the notifications where the situation is normal but significant conditions. Logs are generated with LOG_NOTICE.

- Level 6 refers to the informational messages only. LOG_INFO is the syslog definition.

- Level 7 refers to the debugging messages on the router.

Now coming back to the question where logging trap warning is mentioned on the router. As Warning messages refers to level 4, the answer would be option A.