Answer: D. The interquartile range (IQR) for Town A , 15° is less than the interquartile range for town B , 20°.
Explanation:
The interquartile range is most suitable term to compare the spread of two different data displayed by box-whisker plot.
The formula for interquartile range :-

For Town A , First quartile :

Second quartile :


For Town B , First quartile :

Second quartile :


Clearly , the interquartile range (IQR) for Town A , 15° is less than the interquartile range for town B , 20°.