问题：

[单选]

You are a professional level SQL Server 2005 database administrator in an international corporation named Wiikigo. You are experienced in implementing high-availability solutions， monitoring the database server， and design deployment. In the company， you major job is the deployment， maintenance and support of Microsoft SQL Server 2005. You work as the administrator of a SQL Server 2005 computer， and the computer is named SQL1. The company has backups of all system databases performed every Saturday night， and have backups of all user databases performed every Sunday night. And the company has all backups stored in an off-site facility. Because of the power outage， SQL1 accidentally turns off. And after bringing SQL1 back online， the users cannot start the SQL Server service. You can see the SQL Server error log from the exhibit below. SQL1 should be returned to working order in the shortest time. 
Which action should be performed first？（）

A . All of the user databases should be restored from backup.
B . Setup.exe should be run from a command line and a rebuild of the master database should be specified.
C . The SQL Server 2005 installation CD should be inserted and the setup utility should be run to have the default instance reinstalled.
D . All of the system databases should be restored.