You work as an application developer at Certkiller .com. Certkiller .com is currently using a performance counter named HitCounter.  You are required to increment each time a user accesses the UI classes within the application. To do this， you start by creating performance counters using the following code：  You have to adjust the HitCounter performance counter when a hit occurs. What should you do？（）

• A、A
• B、B
• C、C
• D、D