You work in a company which is named Wiikigo Corp. The company uses SQL Server 2008. You are the administrator of the company database. Now you are in charge of a SQL Server 2008 instance. There is a computer which hosts several applications in your company. The instance runs on the computer. A job named DiliveryList is created by you. This job requires a file to be written to a file server. But because the job cannot access the file server, it fails to run. You intend to configure the SQL Server Agent service so that only the SQL Server Agent service has read and write access to the file server. Which account type should you use? （）