All of the Following Statements Accurately Describe Special Cause Variation

Multiple Choice

All of the following statements accurately describe special cause variation EXCEPT:​ 

A)  It requires specific interventions that include finding the root causes and making changes. 
B)  It is identified by points outside the control limits or by unusual patterns within the limits. 
C)  It is inherent in the system and is predictable. 
D)  It is a statistically unlikely event.