B. A Pareto diagram is used in analyzing qualify problems in a TQM environment. A Pareto diagram is a specific type of histogram. Utilizing the Pareto 80-20 principle (20% of the population causes 80% of the problems), it helps management to pinpoint which 20% of the causes are accounting for 80% of the problems. In this way, it helps management to focus efforts on improving the areas that are likely to have the greatest overall positive impact.

C. A histogram is a method for analyzing quality problems in a TQM environment. A histogram is a bar graph that shows the frequency of events in a set of data. Patterns that may not be apparent when just looking at a set of numbers become clear in a histogram, and problem areas can be pinpointed. For instance, if a particular production line is experiencing most of the difficulty, a histogram can help determine what types of problems are occurring most frequently.

D. A control chart is a method used in analyzing quality problems in a TQM environment. A control chart records observations of an operation taken at regular intervals. If there are trends, clusters, or many measurements outside or nearly outside the specified range, the process may be out of control.