In COPTR practice, what is root cause analysis and which technique is commonly used?

• A. Root cause analysis identifies the fundamental underlying cause of a problem; a common technique is the '5 Whys'.
• B. Root cause analysis predicts future outcomes; common technique is linear regression.
• C. Root cause analysis classifies data by categories; common technique is clustering.
• D. Root cause analysis designs experiments; common technique is factorial design.

Answer: (A)