Implement diagnostics in an application

You are working on a global application with lots of users. The operation staff requests information on how many user logons per second are occurring. What should you do?

Implement a performance counter using the RateOfCountsPerSecond64 type.
Add a TraceSource and write each logon to a text file.
Use the EventLog class to write an event to the event log for each logon.
Instrument your application with the profiler so you can see exactly how many times the logon method is called.