Final answer:
A stacked bar chart is the best choice for showing the sales of DVR devices over the last five years by age categories, as it allows for easy comparison of different segments over time.c) Stacked bar chart
Step-by-step explanation:
The best graphic device to represent the sales of DVR devices over the last five years, with proportionate sales reflected for four age categories each year, would be a stacked bar chart. A stacked bar chart allows for comparison of different segments (age categories in this case) within each bar, which represents each year. This visual format can effectively show the trends in sales per age category over the time span considered.
Pie charts are better suited for showing how a single total is divided into parts at one point in time, therefore, for showing sales over multiple years in different age categories, a pie chart would not be as effective. Line graphs are ideal for showing continuous data over time but may not clearly represent the proportional data for age categories. Scatter plots are typically used for showing the relationship between two quantitative variables, which doesn't fit the description provided.