The first is letter C. The Syslog provider is in charge of giving the necessary storage space that is needed so that the log files will be stored properly without the need to take up disk space. Another answer is letter D. There are various Syslog messages available within Cisco as compared to the SNMP trap messages.
Lastly, the Syslog server will be in charge of the collection of the alerts and logs over a certain time frame. Generally, Syslog is normally used by people when they want to send some event messages to the server. There are different devices that can access Syslog too so it will not be too hard to use.
A Syslog server provides the storage space necessary to store log files without using router disk space. There are more Syslog messages available within Cisco IOS than there are comparable SNMP trap messages. A Syslog server helps in aggregation of logs and alerts.