Because of High Test Costs,a Sample of Single Wastewater Sludge $\bar{x}$

Multiple Choice

Because of high test costs,a sample of single wastewater sludge is tested daily for dissolved oxygen content.The appropriate control chart is:

A) $\bar{x}$ -chart and R-chart.
B) u-chart.
C) x-chart and moving range chart.
D) x-chart and R-chart.