Which type of chart is best used to represent parts of a whole?

A pie chart is the most effective choice for representing parts of a whole because it visually illustrates the proportional relationships between different segments of data as slices of a circle. Each slice represents a category's contribution to the total, allowing for an immediate understanding of how the components compare with each other relative to the overall dataset. This makes it particularly useful for displaying data where the focus is on the percentage or part each category contributes to the entire dataset, such as market share, budget allocations, or survey results.

In contrast, while line charts are designed to show trends over time, bar charts are better for comparing discrete categories, and histograms are used to display the distribution of continuous data. Each of these chart types serves different purposes and may not effectively convey the relationship between part and whole as clearly as a pie chart can.