While completing work associated with ensuring quality in a project, it is important that you know the difference between several different quality related terms. Several of your team members regularly get confused about the difference between the different terms, particularly understanding exactly what a quality metric is.

To demonstrate to your team the difference, you point out that one of the following is not a quality metric. Which one do you point out?

A: Failure rate B: Budget control C: Defect frequency D: Upper control limit