You are a systems administrator responsible for managing a Windows Server 2008 SMTP server.Recently， users have complained that a Web application running on the same server is experiencing performance problems at specific times of the day. You suspect that the problem might be related to loadplaced on the SMTP Server service. Which of the following methods should you use to monitor theperformance of an SMTP virtual server over time？（）

• A、The Current Sessions section of IIS 6.0 Manager
• B、SMTP Server counters collected by Performance Monitor
• C、Windows Event Viewer： Application Log
• D、Windows Event Viewer： System Log