Which of the Following Situations Suggests a Process That Appears

Multiple Choice

Which of the following situations suggests a process that appears to be operating out of statistical control?

A) A control chart in which several points fall outside the upper control limit.
B) A control chart in which points fall outside the lower control limit.
C) A control chart with a series of consecutive points that are above the centre line and a series of consecutive points that are below the centre line.
D) All of the above.