Correct Answer : Agent
Explanation : The SQL Server Agent is a service that lets you configure scheduled tasks and system alerts.
Correct Answer : Master
Explanation : The master database records all of the system level information for a SQL Server system.
Correct Answer : Model
Explanation : When a CREATE DATABASE statement is issued, the first part of the database is created by copying in the contents of the model database.
Correct Answer : Msdb
Explanation : The msdb database is used by SQL Server Agent for scheduling alerts and jobs, and recording operators.