Answer:
Bar graph (chart).
Step-by-step explanation:
A bar graph also known as a bar chart can be defined as the graphical representation of data (informations) by using vertical columns or rectangular bars. When a data set is observed, a bar chart can be used to graphically represent or record the total or overall amount of information contained therein. Generally, bar charts are used for the comparison of informations obtained from a data collection by representing each value (information) with rectangular bars respectively.
Hence, data on DVD sales for three different years can best be compared by using a bar graph (chart).
The bar graph has a x-axis and a y-axis used to represent the various categories of data collected. Thus, the x-axis could be used to denote the DVD sales while the y-axis is used to denote the year.