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 database named Service in the instance. There is a database user who is named ServiceGreatUser. A SQL Server login named ServiceGreatLogin maps to ServiceGreatUser in the Service database. According to the requirement of the company CIO, the database user can only perform the two tasks below: the database user executes all stored procedures that currently exist in the Sales database and executes all stored procedures that will be created in the Sales database. So what should you do to ensure this? （）

A. ServiceGreatUser should be added to the appropriate fixed database roles.
B. You should assign the appropriate object-level permissions to ServiceGreatUser
C. You should assign the appropriate server-level permissions to ServiceGreatLogin
D. You should assign the appropriate database-level permissions to ServiceGreatUser