What does a control chart track, and which type of process variation does it help identify?

What does a control chart track, and which type of process variation does it help identify?

• A. A control chart tracks a process metric over time to detect assignable (special) versus common cause variation.
• B. It forecasts demand for products using time series data only.
• C. It measures only average process output without variation.
• D. It identifies optimal process settings to eliminate all variation.

Answer: (A)