Answer: A.lead to occasional false findings that processes are out of control.
Explanation: natural variation sometimes lead to occasional false findings that processes are out of control when actually, they are in perfect working conditions. In addition to statistical uncertainty arising from measurement errors and so on, other natural systems have an uncertainty associated with the range of natural variability. Natural variation, sometimes just called process variation or chance variation is the statistical description of natural fluctuations in process outputs. When such instances occur (occasional false findings that processes are out of control), there is no one “true” value, and and to avoid tinkering the process, the use of statistical tools such as the mean and standard deviation are employed to describe the natural variation that occured and why it occurred.