The Chief Technology Officer (CTO) of a company, Ann, is putting together a hardwa

re budget for the next 10 years. She is asking for the average lifespan of each hardware device so that she is able to calculate when she will have to replace each device.

Which of the following categories BEST describes what she is looking for?

A. ALE

B. MTTR

C. MTBF

D. MTTF