Which of the following facts are true about X-bar and R charts?

Which of the following facts are true about X-bar and R charts?
A . These are the two charts of monitoring the behavior and the outcome of any process.
B . This is a tool for starting up the Six Sigma.
C . This two chart is used for counting the total manufactured products and the total requirement of manufacturing.
D . It is used for the production of process report in Six Sigma.

Answer: A

Explanation:

This is a set of chart, which is the most important factor of process control, they include the inspection of behavior and outcome of any process of manufacturing