You have a server that runs Windows Server 2003 Service Pack 2 （SP2）.  The server has the Routing and Remote Access service enabled and connects to the Internet by using a demand-dial connection. From the Routing and Remote Access snap-in， you open the properties of the server and enable the Log additional Routing and Remote Access information setting. You need to review the log file for issues related to the demand-dial connection.  Which file should you review？（）

• A、%systemroot%/debug/netsetup.log
• B、%systemroot%/debug/oakley.log
• C、%systemroot%/tracing/ipnathlp.log
• D、%systemroot%/tracing/ppp.log