Pie charts don't have more than _________ categories.

The correct option is Seven.

Pie charts are visual tools used to represent parts of a whole, where the entire circle represents 100% of the data. For a pie chart to be effective and easy to read, the human eye must be able to quickly compare the relative sizes of the slices.

If a pie chart has too many categories (typically more than seven), the slices become very small and narrow. This makes it extremely difficult to distinguish between the slices, read the labels, or interpret the data accurately. Therefore, a common best practice in data visualization is to limit the number of categories in a pie chart to a maximum of seven, often grouping smaller categories into an "Other" slice if necessary.