On a Microsoft Windows Server, the performance counter Processor % Processor time can
indicate an overload situation.
At which percentage is it determined?

A.
70%

B.
75%

C.
80%

D.
85%

Explanation:
http://msdn.microsoft.com/en-us/library/ms178072.aspx
An efficient way to determine CPU usage is to use the counter in System Monitor. This counter
monitors the amount of time the CPU spends executing a thread that is not idle. A consistent state
of 80 percent to 90 percent may indicate the need to upgrade your CPU or add more processors.