What does a box-and-whisker plot summarize?

A box-and-whisker plot is a graphical representation used to summarize the distribution of a data set through its five-number summary. This summary includes the minimum value, the first quartile (Q1), the median (Q2), the third quartile (Q3), and the maximum value. The box itself represents the interquartile range (the middle 50% of the data) and shows how the data is spread around the median, while the "whiskers" extend to the minimum and maximum values, providing visual insights into the variability and potential outliers within the data set.

Understanding this five-number summary is crucial as it provides a concise overview of the central tendency and spread of the data. Each component serves a specific purpose: the quartiles indicate the data's distribution, and the median gives a measure of the central value. Thus, option B correctly captures the essence of what a box-and-whisker plot illustrates.