Final answer:
A box plot is the most useful for approximating the minimum distance as it clearly shows the minimum value within the dataset.
Step-by-step explanation:
The box plot is more useful for approximating the minimum distance as it is specifically designed to display the minimum value within the data set. A box plot summarizes a data set using five statistics: the minimum value, the first quartile, the median, the third quartile, and the maximum value. These are all clearly labeled, making it easy to identify the minimum value. While a histogram displays the distribution of data and could show the range where minimum values lie, it does not specify the actual minimum value. Scatter plots and line graphs are more suited for showing relationships between two variables and how one variable changes with respect to another, rather than displaying specific statistical measures like the minimum.