In building systems context, what is the difference between a fault and a failure?

In building systems context, what is the difference between a fault and a failure?

• A. A fault is a detectable abnormal condition; a failure is the loss of function resulting from faults
• B. A fault is permanent; a failure is temporary
• C. A fault means the system is functioning; a failure means it overperforms
• D. A fault is only about electrical faults; a failure only about mechanical faults

Answer: (A)