单项选择题

You are moving a Windows Communication Foundation (WCF) service into production. You need to be able to monitor the health of the servicE.You only want to enable all performance counter instances exposed by the ServiceModelService counter group. Which element should you add to the system.serviceModel section in the application configuration file?（）
A.<diagnostics performancecounters="ServiceOnly">
B.<diagnostics performancecounters="Off" wmiproviderenabled="true">
C.<diagnostics performancecounters="All">
D.<diagnostics wmiproviderenabled="true">