Final answer:
The correct answer is option a. For comparing sales of different products, a bar chart is the most suitable as it allows for an easy comparison between the lengths of the bars representing sales figures, while a pie chart can become cluttered with many categories and a line chart is more for tracking trends over time.
Step-by-step explanation:
When it comes to representing sales data for the purpose of comparison between different products, bar charts are typically the most effective. A bar chart uses the length of each bar to represent the value of each category, such as the sales figures for different products, which allows for a clear and direct comparison. This makes it easier to see which product is selling the most or the least at a glance.
Pie charts are also useful, particularly for showing how a whole is divided into parts. However, they can become difficult to interpret when there are many categories, as it can be hard to differentiate between slices that are similar in size.
On the other hand, line charts are better suited for tracking changes over time rather than for comparing different categories at a single point in time. Similarly, scatter plots are more appropriate for showing relationships between two sets of data, such as correlating sales figures with advertising spend.
Therefore, for simple and effective comparison of sales across different products, a bar chart is most suitable. If one desires to showcase the products in order of sales volume, a Pareto chart variation of the bar chart, which sorts categories from largest to smallest, can also be particularly informative.