To determine which towns demonstrate exponential growth, we need to look for characteristics in the population growth graph. In exponential growth, the population increases rapidly over time, often appearing as a curve that steepens as the years progress.
Based on the information you've provided, I am unable to see the actual graph. However, if Town A and Town D are the only ones that exhibit a rapidly increasing population as you move along the years, then the answer would be:
both Town A and Town D
If only one of them shows this pattern, choose the respective town. If neither shows exponential growth, then none of the options would be correct. Please review the graph to make your final determination based on these explanations.