Assume an established quality control chart are as follows: X-bar chart is [150, 170), and R-chart is [20, 50). A sample of six performance data were recorded: 140, 125, 170, 145, 156 and 180. Based on the information of sample mean and sample range, and the assumed established control chart, please determine whether the sample process is in control or not. A. Yes, the process is in control. B. No, the process is out of control, because X-bar chart alone is not satisfied. C. No, the process is out of control, because R chart alone is not satisfied. D. No, the process is out of control, because both X-bar chart and R chart are? not satisfied. D B oc