Which of the following visualizations is used to show central tendency and variation in data distribution?

A box plot is an effective visualization for displaying central tendency and variation in data distribution. It summarizes a data set by showing its median, quartiles, and potential outliers. The box itself typically represents the interquartile range (IQR), which captures the middle 50% of the data, while the line inside the box indicates the median, reflecting the central tendency. The "whiskers" extending from the box illustrate the range of the data, allowing viewers to quickly assess the variability and identify any outliers that fall outside conventional ranges.

In contrast, a heatmap primarily illustrates the intensity or frequency of values across two dimensions but does not directly communicate measures of central tendency or variation. A histogram visually represents the distribution of data points across different bins and can provide insights into the shape of the data distribution, but it does not succinctly summarize the data's central tendency and variation in the way a box plot does. A Pareto chart is a bar graph that displays the frequency of problems or causes in descending order, primarily used in quality control and prioritization, rather than for showcasing distribution characteristics.

Thus, the box plot is the most appropriate choice when the goal is to encapsulate both central tendency and variance in the distribution of data.