DS PROBLEM

which is the correct answer

Which of the following statement is true? Warning: This exam question is copyrighted. Student getting help from online services or classmate violates academic honor code and will receive an F Select one a. When monitoring a process having a measureable characteristic either a range (R) chart or a mean (X-bar) chart is used, but never both b. Ap-chart uses the actual number of defects per item in a sample. c. The sample statistics for the c-chart is the sample proportion defective d. A sample point can be within the control limits even when the process is out of control. e. Two types of control charts for measureable variables are p-charts and c-charts