Which of the Following Statements Is Correct

Multiple Choice

Which of the following statements is correct?

A) A process can be in statistical control, yet it can be producing defects in abundance.
B) At least three points outside the upper or lower control limits on a control chart are required before the process is deemed to be out of control.
C) If a process is out of control, then the variation that is present is limited to common cause variation.
D) When special cause variation is present, the process can be expected to be in control.