The correct answer is D. How national borders in a region change over time.
Explanation:
The main purpose of maps is to show geographical features including natural physical features such as mountains or rivers, and political features that refer to the use of land by humans and the divisions created by them. Due to this, through maps, it is possible to visually show cities, states, regions countries, etc. In this context, a series of maps can be used to show the evolution or change of national borders because this is part of political features. Also, other aspects such as policies, beliefs, or economic events are not geographical and due to this cannot be depicted through maps.
