General Idea:
To create a dot plot for a set of data we should list the data from lowest to greatest number. Then create a number line which covers all the numbers given in the data. We need to plot number of circles one above as many times based on the frequency of the data.
Applying the concept:
33, 36, 31, 37, 37, 38, 31, 37, 35, 31, 38, 32, 36, 33, 38
Listing the data in ascending order we get
31, 31, 31, 32, 33, 33, 35, 36, 36, 37, 37, 37, 38, 38, 38
We need to plot three circles above 31, one circle above 32, two circles above 33, one above 35, two above 36, three above 37, and three above 38.
Conclusion:
Out of the four options, the correct option is B because that is the only dot plot representing the given set of data.